I record the sample (generally from vinyl or an MP3 file). Load it up in my audio editor and trim it. Then I chop it up in my DAW. Then I might play around with the chops on my MIDI controller until I get a good idea of what I want to do with the sample. If I want to use 'the low-end theory', I make a clone of the sample, and HPF it. If I want to play my own bassline on top of the sample, I LPF it to get rid of the sample's internal low's.
Then I play the sequence of chops, and from here on I have an on-going process of carving out the right sound that I want from the sample with a parametric EQ.
It depends on my mood whether I EQ for mixing purposes while making the beat. ATM I generally don't - it ruins workflow.
Tip: it's (almost) always desirable to put the EQ after the compressor in an effect chain. If you keep altering the EQ settings through-out the beatmaking session (as most do!), then the dope compressor settings you set earlier likely won't fit any new EQ settings.