Going through the whole frequency range would not be a bad idea! you never know how the EQ is going to interact with your bass, amp, cab, and any other pedals you might have. Having said that...
lows are 50-150Hz, low mids are after that up to 400Hzish, high mids are up to 2.5Khz then after that it's highs
Lows are what you can feel vibrating you (or not)
low mids can be muddy or boomy or tight
high mids can be honky or cutting or growly or smooth
Highs are "sizzle" etc
For a "tight" sound, you probably want less lows and controlled low mids, so a bit of compression and a subtle high pass filter.
It's very difficult to figure out what you mean though. Anyway, on my parametric EQ I have it set to boost 800Hz to give me a nasty gnarly sound for certain sections of songs