You should cut the hair around the pads with a scissor that is rounded at the end. This avoids an agglomeration of dirt between the pads and also slipping on slippery ground. When the pads are free of hair the dog has a perfect grip.
A paw that needs to be cut:
The same paw after the cut:
Also the claws should be controlled frequently. If they don´t wear off enough please cut the claws with a claw nipper. Since this can bring a painful lesion your vet should better show you how to cut. Please don´t forget the dew claw!
Some various claw nippers I use:
In winter it is expedient to attend the pads with a protect cream. Ice and de-icing salt stress the pads bad.