A good source of workshop inspiration is the Library of the workshop planning tool SessionLab. There you can find more than 1500 different workshop ideas, including exercises to warm up the team, find ideas, decide, etc.

Here a few other alternatives of such libraries of facilitation techniques:

I've also created a few workshop tools and templates to help you.

To go even further, Chris Corrigan has a big list of facilitation resources that might interest you.

Check out all the questions about workshop facilitation and service design.