Generally, the best man acts as the toastmaster, and prepares a list of the order in which each person will make a toast. There is an established protocol which the couple may or may not choose to follow.
Microphones: You may want to check with the hired musicians for the use of their microphone if the rehearsal or reception is in a very large area and people may have a hard time hearing. You might also consider if the sound system will be set up when you need to speak.
Special Considerations: If you, or someone else, will not be able to stand as you deliver your toast, you may want to make special arrangements ahead of time to move to a location where you will be seen by all.
Rehearsal Dinner
You might follow this order:
During the Reception
You might follow this order:
Tips for that Perfect Toast