I agree with Andy. Red decal strip will do the job for the rectangles. I just received some from Hannant's for a similar need (pics attached - if the 'system' is working. Can't see Andy's pic).
The 'No Step' decals can be made on the computer, in 'Word', using suitable font, and then printed on to clear decal sheet, which should be available from a computer paper supplier, either per sheet, or in packs, and is the same stuff sold by such companies as Testors, although a lot cheaper.
The printed decals might not be as 'sharp' or as dense as commercially produced decals, but for such things as stencils, they are normally good enough. Once printed, leave them for at least 15 minutes, in order for the ink to dry, and then spray them with a good quality artist's acrylic gloss varnish to seal them, leaving this around two hours or more before using the decals in the normal way.
When producing the decals on the computer, you don't need to keep typing the same word(s). Instead, use 'step and repeat', by typing the word(s) for one decal, 'highlight' this with a 'left click', then press 'CTRL - C'.
Then place the cursor at the end of the highlighted word(s), and press 'CTRL - V'.
This will repeat the already typed word, and continuing this process will repeat as many times as required.
Sizing can be adjusted by either the font size, or outlining the word() and using the mouse, diagonally, to expand or shrink the image.
I've attached a pic of some 1/48th scale Spitfire stencils I made using the above method.