Grip from the centre
If you are a starter, you should be know where to grip the spear from when you are about to throw it. The ideal position is the centre of the javelin, as that will provide you the best grip than any other position.
Powder your hands
There needs to be no moisture on your palms when you grip the spear. Some people may not have sweaty hands while gripping the javelin, but they might end up with moist palms on the point of throw. In order to avoid this problem, you have to powder your hands properly. This will allow hurling the javelin as far as possible.
Do forearm exercises
You need to have a strong forearm in order to grip the javelin firmly. So, make sure that you exercise properly in order to get a good grip. Don’t try lifting heavy weights in the gym, but the important thing is to keep your muscles flexible.