Solo Development
One must remember when developing a Solo character you must be willing to make some sacrifices but in turn there will be rewards. Any race/profession combination can be used in a Solo game. Some, naturally, will be more difficult than others. There are ways too numerous to mention on how to develop all the possible combinations so what will be addressed on this page are common difficulties a Solo faces and some options to help cope with these difficulties.
 
I) Encumbrance: One of the most difficult things about developing a Solo character revolves around material objects. Carrying Capacity for a party is calculated by the strength of all characters in the party. With several individuals in a party the weight is shifted and distributed as evenly as possible among them. Of course with a Solo your carrying capacity is based solely on that one individual. The higher your character's encumbrance the more negatively it impacts their performance. It will reduce their armor class, initiative, attack rating, and increase the stamina drain while performing any tasks in or out of combat.

Whether it be items needed for use or accumulated items for sale your Solo will have to make adjustments to accommodate the decreased carrying capacity. Some possible compromises:

1) Increase the character Strength either via attribute increases at creation and level up and/or obtain equippable items that give increased Strength. This will help to offset but not totally solve your capacity problem. 
2) Grab only what your Solo can handle and make repeated trips as needed.  Only pick up items while in an area your Solo can use. When you are ready to leave the area take only items your Solo can use or identify so they can be sold readily. Return for salable goods at your discretion and as monetary requirements dictate.
3) Magic. Though it comes a bit later in the game a profession that has magical spells can always set a portal at their favorite vendor so they may teleport back to purchase more items that are running low or sell off items that have accumulated.
4)  Make use of your surroundings. There are a few teleporters on Dominus that can take your Solo near towns so you can access vendors more readily. These teleporters can then return your Solo near the areas they have left. Your Solo will still need to do quite a bit of walking.
5) Hire item recovery assistants: Hire a couple RPCs to run about on item recovery missions. Hire them long enough to grab up items left lying about in various areas and have them accompany you long enough to sell off these trinkets then give them the boot.

6) Start a character who has the Alchemy skill so you don't care about the items lying around because you are already rich as Donald Trump and could care less.
II) Gold & Items: Every character has a need to purchase something during the course of the game. Performing quests and selling items are the only options to make a decent living on Dominus. A Solo does require less funding than a full size party but they will need gold to meet their needs. 

Obtaining enough gold to get by on can be difficult if your profession has no way to identify items. Selling unidentified items causes your Solo to take a big loss of funds. Some unidentified items can not be used. Those that can be used while unidentified have various outcomes, not all pleasant. Some things your Solo can do to work around this:

1) Starting a character in a profession that studies from the Divinity or Psionic spell book will resolve this issue since they will have the Identify Item spell at their disposal in time.
2) Use scrolls of Identify Item. These are limited and will not be able to identify all items in the game.
3) Train the Artifacts skill at every opportunity. Store unidentified items in chests near vendors or close to teleporter access if need be. As the skill increases sell off newly identified items. Be willing to accept the fact that some items in this game require over 100 Artifacts skill to identify and you will never identify them unless your Solo can take advantage of # 4 below.
4) Make use of any items with an Artifact Skill bonus. There are only two items in the game, both fairly rare, that increase the Artifacts skill. Prospero's Cloak and a Philospher's Shield. (Examine their information for all race/profession restrictions.)
5) Hire an NPC who studies from the Divinity or Psionic spell book and level them up to a point where they can make use of the spell. Hire them to identify items while in their area.
III) Magic & Resistance: Whether or not your Solo will be in a profession that can cast magic spells you should plan accordingly. If your Solo is of a profession that has no magic skills you can compensate for this in a couple different ways.
1) You could choose a race that has normal to good magic resistance. Selecting a character that has no negative resistance to the various realms is a good idea. Some of the most debilitating or paralyzing spells of the game hail from the Mental, Earth, and Water realms. Some of the deadliest spells are in the Air, Earth, and Divine realms.
2) Compensate for the lack of magical protection by obtaining items that can either cast protective spells or increases any realms your Solo might be weak in. 


There are few items that provide resistance bonuses to all realms, but there are several that provide a bonus to one realm. Keep items on hand that provide various resistance bonuses and equip them in areas where they will provide the best protection. For example you may wish to have items that protect against the fire and water realms while in Rapax territories but on the Arnika Trynton Road you may wish to have an item to increase earth resistance. 

See the Individual Items Index and browse through the items available in the game to see what options may be available to your Solo. Most items will be found in the Cloak and Misc. Equippables categories but there are armors and a few weapons that provide resistance bonuses.
 
IV) Experience & Leveling Up: The biggest advantage of the Solo is that they do not have to share experience with other party members which will enable them to level up more quickly. Ultimately they will achieve a higher level by the end of the game and will be able to maximize more attributes and gain the use of more expert skills. This sounds pretty terrific, and it is, but you need to examine this a bit more closely.

Skills increase through use more than any other method in the game. With more experience resulting in faster level ups your character will not get to practice their skills as often. Throughout the game Monsters are spawned based on the Solo's level of experience. So if Monsters spawn to match character level but a character's skills are the equivalent of some one half their level, you can see the problems this will lead to.

1) You may wish to hold back levels ups until your Solo's combat, defensive, and/or magical skills meet a predetermined level. For example you may keep your Solo at level 1 or 2 until their skills reach around 20. Hold level 3 back until these skills make 25 or 30. 
2) Another idea is to set reasonable expectations for the Solo based on the game difficulty setting you are using. Once the Solo seems to be handling the monsters in their area quite effectively, regardless of skill level, increase to the next level of experience. If they are having difficulty hold off leveling up until they are skillful enough to deal with their foes.
3) You can always make use of power training methods to increase the Solo's skill level to a point where the skills are more in line with their character level.