Hi Angela and welcome to the forum,
I think you just need to ensure you're providing good products, good customer service for your agents and good, clear policies for your agents. Things like good marketing images, CSV files to make marketing as easy as possible for agents as well. Of course providing value is always important and I would always suggest incorporating bonus schemes for agents as well.
Rewarding those that are moving good volume of your products by offering special deals, better discounts or similar. That shows your agents that if they're prepared to push your products for you, then you're prepared to support them in building their business as well.
Cheers