I do LIGHT rolling before exercise with a smooth roller, and before my dynamic warmup. I save the intense rolling for either well before exercise, or after. Typically after.
How do you know if you're rolling too hard? You'll know. Honestly, it's hard to generate excessive pressure on the tissue via rolling. And pain is always a great indicator. Some discomfort in a tender area while rolling is ok. Intense pain, not so much. Trust your instincts. Don't be afraid to go deep, but don't go crazy.
Volkl Organix V1 Pro
Pacific Gut 17 gauge mains at 54lbs/MSV Co-Focus 17L gauge crosses at 50lbs