Better than flops seen, is to use the Voluntarily-put-money-in-the-pot percentage(VPIP%). Flops seen does not account for the times you bet and everyone folds, and counts the times you were in the BB and checked, so it's not helpful to know if you are playing too much hands or too little.
For a tight strategy a good VPIP% in 9 max lies between 11 and 18, and 18-25 for 6 max I'd say. A more loose strategy would be seeing numbers up to perharps 30-33% at the very top end. Approaching 40% you have entered fish teritory