1. It all begins with your approach. Slow down really early and look as early as you can into the road on your right, and across the roundabout itself. By watching the traffic flow really early, you can sometimes slow yourself down and take an opportunity to go. By timing your arrival at the roundabout when there is a gap is a great way. By practicing this you will find that you actually stop far less often.
1a. Remember your brain is really good at spotting what you tell it to, so if you get it to look for cars it will almost always find one and make you stop, so look for gaps.
2. If you do have to stop, ensure that your feet are ready to go; try to avoid just sitting with your foot on the brake and clutch down. The longer it is going to take you to get moving, the bigger a gap you will need. Exactly how you set your feet will depend on whether the surface you are on is flat, uphill or downhill, but you can experiment with different situations like being on bite with gas set if it’s uphill.
3. Practice moving off quickly, I call this ‘drag starts’ like the drag races. Park up somewhere in a quiet road, and when it is safe, see how quickly you can get moving such as saying 1, 2, 3, go. This will help give you the confidence to pull out into fast moving traffic at busy roundabouts.
4. While you are waiting to go, think about where you should be looking. Don't look just at the cars which are coming from the right, look beyond them to try to see the gaps. As mentioned previously, try to have your feet ready and anticipate the gap so that you are ready when it comes.
5 Look at the other junctions for ‘blockers’. If there are 10 cars coming from the right, and no gaps in sight, who is going to stop those cars? Who are THEY having to give way to? It may be a car coming from straight ahead of you, or even from the road on your left, if it is turning right. Again, try to anticipate this happening and have your feet ready
6 Most of all, just practice! These are all (hopefully) helpful tips, but the main thing is to keep practicing by doing lots of different roundabouts (different sizes/shapes etc).
Hope this helps....