There is no set rule about when the speeches should be made. It is important that the bride and groom think through the structure of the whole wedding reception before deciding on the exact timing.
Some couples opt to have them early on, before eating, especially if the speakers may be nervous. Others adhere to tradition and have them after pudding.
At a seated reception, some couples have the speeches after the main course, but before the pudding. Alternatively they can be after the starter, but some caterers may find this inconvenient for timings of a hot main course.
A glass of champagne for the toasts should be distributed before the speeches start.
Some couples opt to cut the cake before the speeches to prevent the moment from being overshadowed by the aftermath of the speeches.
If the reception is drinks-only, then timing is crucial; after an hour and a half is normally about right.