The following rules of etiquette have been around for many years and are still practiced today by the majority of dancers:
Travel in an anti-clockwise direction around the floor
When appropriate faster moving dancers travel around the outside track with slower dancers taking an inner track
The person moving forwards should look out for other dancers and signal to partner by squeezing their hand or tapping their back if a collision is likely. If you do collide then apologise to the other couple irrespective of perceived fault.
If the floor is full then do not try to perform advanced routines, you will not manage to dance them properly and will annoy other dancers. Perform basic steps with lady paying attention to partners keep steps small and arms in if necessary
It is acceptable to decline an invitation to dance if you are tired and need to sit the dance out otherwise you should accept and say thank you at the end of the dance. Man should escort lady back to her seat.