Help!! I am single and have tried all different kinds of anchors. They either deform, fall out, cause the item to droop or just don't work. I have googled tutorials and I just can't get them to work. I used the one that came with my shoe cubby, a large plastic one you need to fit in the whole and it is supposed open up behind the drywall, bit I can't get them to open. One fell through and the other just spins with the screw. I am at a total loss and completely frustrated. Any help would be appreciated.
The part of your issue where you said "One fell through and the other just spins with the screw." tells me the hole is probably too big.
Did you use the recommended drill bit size to make the first hole? When you drill the hole, take care to keep the drill at 90 degrees to avoid widening it bigger than the hole is supposed to be.
Some of the drywall inserts want you to hammer them in, and then they bite the paper, others you use a screwdriver to tighten them in.
Are you using the same screw that came with the anchor? Be sure to use the same screw meant for the anchor.
Are you in an unusually humid area? Its a bit of a reach, but high humidity doesn't help. Also, is the drywall 1/4" thick? The thinner the drywall the more issue you will have with mounting drywall anchors. Other than measuring the drywall from the already existing holes, or measuring the thickness from near a floor board, (or perhaps turning off a breaker and taking off a light switch plate and measure the thickness there, dont use a metal ruler for good measure).
If you need to still use the hole already made and it is too big, you can try a wall anchor with a toggle style as an example.
The other wall anchor type, which are far better than the cheap plastic ones, actually have a tooth to bite into the drywall, and are much better quality, look like whats pictured in #2 at the following link. These are Molly bolts and will do the job nicely: Molly Bolts @ #2
I have had good success with this type. They are widely available and you don't need to drill a hole. You force the point into the drywall and then screw it in with a suitable Phillips head screwdriver. They come in different sizes. Screw in drywall anchor