Here are some handy exercises to streach your co-ordination
Here a list of limbs to go with the chart. As you can see it it involves playing singles against doubles on all limbs or the other way round depending on which one you start with.
1 LH 3 RH 2 LF 4 RF ----------- 1 LH 3 RH 2 RF 4 LF ----------- 1 RH 3 LH 2 RF 4 LF ----------- 1 RH 3 LH 2 LF 4 RF