Last time i checked you can get some decent free eqs from voxengo including a stereo eq to mix left and right differently (good for creating a stereo spread of thickness) to be honest any eq with Spectral anaylser (visual eq display) and high resolution controll of filters such as high/low pass and cut, as well as peaks. To be honest in most of the studios i use they have completely different plugins, you need to improve you general ear and mixing techniques as well as learning the general tricks for each genre. when you mixing an instrument you need to be able identify the frequency bands and there "sound" ill give an example. if your mixing a bass sound a pretty general good sound can be got by applying a high pass filter at about 40-50hz (use your ears!) to cut out any sub bass, (this is also a good tip for getting clearer bass in a master, since your speakers probably wont even play sounds under 40hz. also for a bass you might want to dip the frequency at around 300-400 hz because this is a very wooly/muddy area which is fine for some music but for a punchier or clearer sounding bass scoop out some of the 300-400 and possibly boost around 1-2khz again use your ears. you cant always do the same thing since not all audio sources are the same. That being said once you mix things on a regular basis, you do start noticing the corrections you can make pretty quickly. creative eq can come after. sorry for the essay! if you want any tips mixing a particular instrument im happy to answer. finally when mixing an instrument make sure you consider other instruments in your mix that could potentially cause destructive/constructive interference or phasing, ghosting whatever you want to call it, for instance if you have alot of 1-2khz in your bass drum (for punchy ness) you might want to cut abit out of your bass and perhaps other instuments