Define yourself.
Sketch out background of your character (doesn't have to be detailed, but must be existent) and minimal code of behaviour (nothing too LARPy, just general behaviour and stances on basic stuff - slavery, murder, stealing - something to create a basic personality and keep you from functioning in vacuum), make it into a build, then try to stick with it.
As for actual gameplay, you may try making an honest spellcaster. No "durr hurr will wield long sword for moar damage" or any shit like this - just you, spells, robe on your ass, some light self-defence weapon, and INT and WIL every level. Should give you good incentive to play with spellmaker.
Also, no or very little training, no grind, and no abusing obvious exploits, glitches and loopholes.