What you need to know
Round the windward mark to give yourself the opportunity to get to your selected side.
Sail as straight as you can and as close to the rhumb line as possible.
Hopefully you chose which side of the run to go before you start the leg and position boat accordingly. Sail the boat as straight as you can and as close to the rhumb line as possible. This is where your practice will come in handy, the boat tracks in a straight line, you can gybe with minimal change in direction by using the winch, you goose wing quickly and efficiently with minimal change of course.
Watch for boats behind covering yours. It is best to try and steer clear of other boats behind as they will always try and take your wind. Better to make a definitive move first into clear air than be forced into it later as you fight to keep clear of boats behind.
By keeping clear of other boats you also avoid luffing matches and can stick to your plan.
Look ahead and plan for the leeward mark/gate rounding. Which mark will depend on which is closer and which side of the beat you want to get to. Position boat accordingly.
Always watch upwind for puffs and be prepared to alter plan to accommodate them. It might mean a gybe and a significant change in direction to get to the puff.
Position to be the inside boat at the leeward mark as you can make significant gains if you get the approach right.
Finally the most important thing on a run is to remain calm and take slow deep breaths to calm down after the excitement of the start first beat and mark approach.