using a 'silhouette portrait' usb vinyl cutter, and some software, I often bring images.google.com stock into photoshop, edit and scale the bits I want, then bring a .png into the 'silhouette studio' wherein I play with trace options to get an optimized cut.
I first load in the vinyl, matte (reverse) side up, which has been cut to the size I intend to print, taped with scotch or electrical tape.
the image, itself, is also flipped horizontally in the program, for iron-on, or non-flipped for sticker/adhesive..
I bought sample packs of both iron-on and stickers.. so I have most imaginable colors.. and everything looks good in black
as i use a 'hook' to pick out the negative space, I then also consciously peel along its lines, observing any 'printable vinyl' I may be about to damage.. in those cases, say an incomplete cut - I use a blade to force a cut on its edge.
the cut is complete, after picking into the 'relief' portions of the cut. I chose this particular image because it had that 'texture' and I thought it would be easy to trace and cut.
I was right.. it looks rad.. do notice tho the border cuts are duplicated.. I probably could have spent more time doing 2 traces, an outline, then the relief bits.. this program does not accept line-art, EPS, which is a bummer.... sometimes I upscale a smaller image, which helps me get a better cut.. especially if things are horizontal and vertical, i.e. just lines.
iron on with a paper 'shield', such as a paper bag, so as not to melt vinyl onto the iron, about 15 seconds.. and done!
throw that over a long-sleeve undershirt, find a cap, suit up, and we're good to go!
this was the original image: