Non stop begonias

What plants are good to plant along with Non Stop Flowering Begonias. Or are they best left planted thogether. I want to plant up some tubs.
Can anyone give me any ideas as to what plants are best mixed together. The tubs will be in full sun.

Thanks

 

I missed this celt, seeing as non stop Begonias are upright in habit perhaps something trailing would go with it (depending how high the containers are) such as Bacopa, trailing Alyssum or even edging Lobelia. There are many plants you can mix with Begonias, Salvias, impatiens or even Geraniums. Trial and error is part of the fun of gardening so really you could try anything!