Your instruments should be close to being finished. The next step will be to record the sounds these instruments make for use as sound in the next project a Performance Video.
Recently Trent Reznor of Nine Inch Nails was interviewed by Terry Gross of NPR's Fresh Air. They discuss Reznor's recent work on music compositions for the movies, Girl With the Dragon Tattoo and Social Network. Reznor talks about the use of found and experimental sound he uses throughout his work to create a certain feel and mood that complements the movies he is composing for. This is your goal with these sounds that will be produced by your instruments. The interview can be found here;
"How Long" by Trent Reznor and How To Destroy Angels