How do you eq your various instruments?

     Good at getting my drums and vocals the way i like them, but i have trouble with guitar, pianos, synths.... i feel like guitar and synth are fighting for the same spot in the mix, where do you prefer to "sit" things? I know each mix is different but give me some good places to start, for the purposes of rock and hip hop

One way often mentioned is to never boost, just cut other stuff instead.

And panning of course to separate things.

And finally you mention "guitar, pianos, synths", it sounds maybe too many things - soundwall.

Arrangement might be the thing to adjust - and choosing instruments that don't overlap too much in frequency content.  Not all instruments need to sound all the time - make the mix breathe.

Each mix varies. In addition to the HP & LP filters mentioned one thing I do is set up a EQ band with a very narrow Q and high gain. Then while the full mix is playing sweep the frequency pot and you'll find 'sweet spots' as well as some really poor spots. I usually find a couple of the sweet varity and one maybe two of the poor type.

Set your other band's frequency pots to those sweet & sour spots. Then use a combination of cut and boost to get the sound to sit how you want it to. Narrow Qs tend to work better on cut and wider Q's on boosts. I tend to cut more than I do boost but I don't follow that as a hard and fast rule. Depends on what I'm after.

This may be the way everyone works but I will share it anyway,.... The best advice I ever had was to keep every instrument (apart from drums) in mono and use panning to separate frequencies. Pretty much as a rule, I use the High Pass Filter on everything but the bass and kick drum which I use a Low Pass Filter on. EQ to suit after that but remove don't add or the highs will become harsh. I know that you cannot use the same 'formula' for every mix but I find that if I stick to these rules it makes mixing easier.