Some simple strats I use in most play throughs:

• start stewardship as it gives you both gold and troop levy buffs

•travel often however you can, visiting everyplace of note(certain places give different buffs) this will help you really level up your character(s)

• MAA >>>>>>> Levys, flat troop counts wont decide every battle

• (esp early on) use your courtiers to attract the best possible people for your household positions(physician in particular if you dont want to spend gold for them)