I am a do-it-yourselfer and I've roofed my shed with 3-tab shingles.
(First roofing job) I plan to cut my leftover 3-tabs to make the cap
shingles.

It sounds like I install these in a similar manner as the rest of the
roof... overlapping.. leaving 5-inches exposed.

But how do I install the very last cap shingle? Am I supposed to use
adhesive or something? Or lift the last shingle and do the best I can?

Thanks for any help.
Buzz