I thought the shift on mine was pretty pants, so I've done three things to improve it and they really have made a big difference. (I think all three came to under ÂŁ200)
1: Motul Multi DCTF transmission fluid.
2: Boomba shifter base bracket.
3.Powerflex tranny insert bushing.
One of the best small mods (although quite expensive) is a 5 spur cup holder cover. It is amazing quality and much better than having my elbow in the cup holder.