The long ball: an essential
You can also make the most of the quiet period to work on your long ball work. Whether you're a defender, centre, or attacker, it's very important to master this aspect of the game.
You can train by practising with a friend standing still and/or running forwards and trying to kick it to your partner as you run. At the same time, you'll be working on your ball control, because of course "bad control" equals a lost ball!
You can also do games to work on the precision of your long kicks, using a small inflatable goal or cones for example. Stand 20, 30 or 40 metres from the goal or any other object you're using as a target and try to hit it as many times as possible. To liven it up, you could try making it a competition with another player.