I have two issues about enclosing/casing electronics:
I have some leads connecting each other with a few resistors in between. I have put the resistors and wire connections on a small piece of stripboard and want to enclose somehow just to look better. I've considered shrinkwrap, boxes from maplins (which need filing out for leads to go in), fimo (to encase and bake) - but don't know the best solution that other people use - or is it always just bespoke?
I have a PCB with a number of jack connectors and want to enclose in a case - any recommendations for case companies that will make bespoke cases? will they use the pcb design software to make cases?
The polymer clay (Fimo) is probably not a good idea as it may contain compounds harmful to the electronics and the baking temperature may be too high.
If it's just a few resistors on a board, I often just use shrinkwrap as you do. Otherwise you can encase them in potting epoxy. This is designed to be safe for electronics and just about any kind of enclosure can be used as a potting form.
If you do much taking things apart, you could use the plastic case from a wall wart transformer.Those work well for many things. If it is anything to do with RF or sensitive electronics, you will want to use metal to shield/encase it.
Id be more concerned about putting a strain relief on those resistor board cables. It looks fragile as hell. You could get a solderable 3.5mm plug and put the resistors (1/4 or 1/8 W fit nicely and there are some plugs that fit 1/2W too) inside the plug's casing, so you wouldn't even need the strip board.