Choose very wisely who you ask to speak.
If you have lots of people (family or friend groups) that you want to speak, see if they can’t get together and present one speech on behalf of the group .
Don’t force people who you know aren’t confident speakers to give a speech. If they refuse on these grounds, it’s not because they love you any less. Perhaps they know they are doing you a favour.
Give time limits to people, and ask them to stick to them. Long speeches are never fun for anyone, and can put a real stop to the flow of your evening.
Funny speeches work, as long as no one is offended along the way – there is nothing better than a dining room full of people rolling on the fall laughing, as long as they are ALL laughing.
Ask guests for paper copies to for keepsakes (even rough ones)