Take a trip to a craft centre, like the Dancing Pots Craft Centre or the Cards for Africa workshop and sales room in Kigali.
Your best bet would be with an aid organization or NGO. If you are a resident of the US or EU, keep in mind that you can avoid paying for an expensive residency permit simply by declaring yourself a tourist upon arrival and then traveling outside of Rwanda once every 90 days for the length of your day. Your 90-day tourist visa automatically granted upon entry will be renewed each time you leave and reenter the country and it's a convenient excuse to go on vacation!.