Equip as much magic find to your character as possible and go kill stuff and open chests, loose rocks, barrels, ect. Also kill Champion and Unique monsters for a better chance of getting good and rare items. If you have 100% or more magic find does not mean you will always get rare items, if you have 100% magic find, then you have 2x better chance of getting good items. Champion, Enchanted, Unique, Super Unique, and Bosses have a higher chance of dropping Rare, Unique, and Set items then regular enemies. Try getting to a very high level(45+0 and get really good magic find and kill Baal on normal by yourself(So other people cant take your items) a few times, you should get at least 3 rare items if your magic find is very high(150%+). There is NO limit to how much magic find you can have, but sometimes magic find items can be weak.