Many who have been involved in amateur astronomy have, over time, come
up with relatively simple, homemade solutions for common problems.
This thread provides an opportunity to share your solutions with
others.

I'll start with very simple one:

Some tripods don't come with shelves. For others a shelf is an option
for which one is charged an additional fee. I own tripods that fit
into each of the above categories. In the latter category the added
fee was in my opinion too much to justify, especially when I felt I
could easily build a better (larger) shelf myself.

My solution: I set up the tripod, made measurements to determine how
large of a circular shelf could be fitted and placed on the tripod's
bracing, and cut out a disk of appropriate diameter from 1/2 inch
plywood. A pair of holes were drilled near the outer edge of the
plywood disk above each of the three tripod leg braces. I used pieces
of leather cut from a leather shoestring to attach the shelf to the
tripod (utilizing the drilled holes). On one of my shelves I added a
central machine screw that fits through a central hole in the center
of the tripod's bracing. A couple of washers and a wing nut are added
from the bottom side of the shelf. The final step was painting the
shelves.

Circular shelves can be made with a larger surface area than the
triangular shelves that are available with many tripods. I have no
need for a raised border (can get in the way of large objects), nor
for holes drilled for eyepieces (a smaller object could fall through a
larger hole). I prefer a solid, flat shelf that can be used for
anything from a temporary support for counterweights, finders, and
diagonals through longer term support for eyepieces, flashlights,
clipboards, binoculars, etc.

So what kinds of simple solutions have others found for common
problems?

Willie R. Meghar