A good general rule for EQ: Make your cuts narrow and your boosts wide.
That is, when removing frequencies, remove only what you need to. On a parametric EQ, use a high Q value, and identify specific problem frequencies. The less you cut, the more natural the result will sound. Conversely, when you boost a frequency range, narrow band EQ filters can introduce ringing. Broad, gentle boosts (i.e. low Q value) are less obvious, which again yields a more natural sound.
If you can’t play a part, don’t record it.
Practice until you can play it, or change the part so it’s easier to play. If you don’t nail the performance, it will show in the recording.
Stock your recording space with spare parts
Stuff breaks, but with a good emergency kit on hand, it doesn’t have to mean the end of a recording session. This is especially true if you record other people: Don’t trust the guitar player to remember a spare E string, but count on him breaking the one on his guitar.
The essential emergency kit: A multi-tool (like a Leatherman,) guitar strings and picks, drum sticks, band aids (!), instrument and microphone cables. And duct tape. No recording studio should be without several rolls of duct tape. You can keep a busted guitar together with enough duct tape. (Don’t ask.)