Feats are a precious resource: most characters get seven over the course of their entire career, with humans getting eight and fighters getting eleven more... but at the dire cost of having to be a fighter. That's not even taking feat taxes into account, with many of the more desirable prestige classes necessitating one or more feats that are otherwise of little to no use.
So how can you ensure your feats are working hard enough for you? In particular, more specific feats might have a strong effect, but they run the risk of being useless in most situations. Well, there is a rather simple way to not only get more feats, but to get them on-demand, picking up whatever suits the situation as you need it.
There's a little gem in the Spell Compendium called heroics - a level 2 sorcerer/wizard spell that lets you grant the subject a single feat off the list of fighter bonus feats for 10 minutes per level. Even at minimum level, that's half an hour to make use of your new feat. Having to be a fighter bonus feat is indeed a big restriction, especially from your viewpoint as a spellcaster - no crafting, no metamagic and nothing along the lines of spell focus, obviously. But if you look, you might be surprised by how extensive the list really is, often with bonus feats appended to it with every book. In particular, versatile feats that grant you choices gives you a 'feats-within-feats' situation that can be tooled to suit any character.