Before going sailing we had a look at an RYA training video, filmed in sunny Majorca. The main thing is to remember the five essentials and to apply them: for that you need to have 'feel' for where the wind is coming from. This should now be getting much easier with experience, and indeed is, looking at how everyone is sailing.
Course made good is the main thing; balancing where you want to go with the wind, both direction and strength. Running dead downwind isn't very stable: the sail is right out on one side, and all the force is from behind which means that the boat wants to bury its bow in the water. This isn't a major issue with Toppers but gets interesting with bigger boats. You might want to sail slightly higher and then gybe to get to the downwind mark.
Remember that a gybe brings the boom across very quickly, so be prepared to duck and to balance the boat.Occasionally you can get on-board problems; e.g. a rudder coming up. If this happens, let your sail out and turn the boat head to wind; this calms things down while you sort it out. Moving your weight to the back of the boat will bear it away so watch out for a gybe. Everyone is also much better at landing now; remember that the wind can change since you went out, but it's still important to approach the pontoon from downwind. (We help by blocking the 'wrong' side with the rescue boat!)