I've tired renting a space, didn't work. Give it a shot it's a great
education, everyone should do it once or twice. Good way to lessen the
clutter too.

One thing about prototyping is than one needs to be proficient on the
design side and skilled with the software of your flavor. That for me is
the joy in the hobby. Having someone describe an object, I ask for a few
exact dimensions and boom they are looking at it on the screen.

 If you just cranking out widgits then its production. I'm not going to use
my machines good years on production items because if one is or none are a
winner I'll then be faced with other problems. Like time lines, down time,
repair cost,, limited prototype time etc..

I start thinking about what items I've made the most of and what items have
been most useful to others. By far the safety whistle I've made the most.
People love them, and the bullhorn attachment raises eyebrows too, works
well saving the users ears while directing the blast. Dog owners bought the
only two at $4 each.

The item that has had the most use has been the replacement kitchen utensil
handles. Most of my neighbors are old and arthritic and need a better grip
on the bigger spoons and spatulas. I've made a half dozen so far and I've
got four more brand new utinsils sitting here waiting to meet the hammer
for an upgrade. But thus far those are freebies. I'm not going to ask for
money from 70+ year old ladys.  But if it takes off into a real three a
week, each special made with two colors then I'll put $10 on each.

Now, if I was a good artist like my niece I'd be banging out custom
refrigerator magnets all day.  

Like all my endeavors into hobby cnc it takes a while to find a niche and
most of the time its what you already know or do as a hobby. When you find
it you'll know it and a whole new level of responsibility will follow.