What you need to know
Have a plan
It is not necessarily how you approach the mark it is how you depart from it
Position boat to take the favoured side of the beat.
Have a plan for the mark rounding. Your goal is to be the inside boat which can be difficult if there are a bunch of slow boats in front of you and you have to take avoiding action. If in doubt, with a bunch of slow boats on the mark and you cannot get inside, sail round the outside of them.
If you are clear of other boats or have "Mark Room" on the boats around you, enter wide and exit close so when you start the beat the mark is along side you and no one can get inside you. Ideally position the boat so you are in a position to tack if needed and sail to chosen side of course on next windward leg
Tack for clear air immediately if there is a boat close in front of you. They will only slow you down and you will have to tack eventually as you fall to leeward into dirty air from the boat in front. There is a proviso here that the tack will take you into clear air and not back through the fleet. Sometimes the better option is to eat dirt until you can tack into a clear lane or foot off into clear air if that option is available. It all depends how many boats are in front of you.
Finally remember when overlapped in the zone at the mark, port and starboard no longer apply
Video example 1 3 boats in a line, better be the inside boat
Video example 2 Avoid getting trapped as outside boat. It will end in tears