Here are a few that are very handy and true.
Floss
12 to 14 inches of floss at a time have greatly helped my frustration of the floss twisting up on my in mid use and knotting.
With the floss twisting up on me, I will hold my project out in front of me and let the floss hang to unwind itself from the weight of the needle. Just make sure the needle wont fall off.
I find the less floss you have on the needle, the easier it is to pull through the fabric. I use about three strands at a time.
Nice and tidy storage is the key to less stress! To me anyway. Still wrapped in the bands or wound neatly on a bobbin.
When I first started (cross stitch at the time) I pulled way to tight, and all my stitches were uneven. It looked shabby.
The size of your needle plays a big part in the appearance of your handy work.
-Not too large to leave a large visible hole in the fabric, not too small to not be able to even thread it with multiple strands. Play around with the size that you would need for a project.
Also be aware of the type of fabric you are stitching on. Canvas is a very thick material, and can be diffacult to stitch with a larger needle.
Stabilizers
I use couple of different types of interfacing for my stabilizer.
For dark fabric I transfer my design on the interfacing itself and put it on top of the fabric and start to stitch.
If it's a thin or stretchy material, I'll use a thicker, but not so thick to where you can't poke a needle through it and fabric comfortably, underneath.
Colors
If you have a project that requires a lot of colors in small areas, try to have a couple of needles already threaded in the colors you need.
If you want to color tint (color with crayons), do so before you start stitching.
Other
A nice sharp pair of scissors are your best friend.
Back stitching can be the devil, but a necessary evil, just like french knots. But with practice, they become very easy.
Well, back stitching is very easy to start with just a pain in the neck.
And speaking of which, Keep your shoulders relaxed. Try not to bunch up.
I hope that this tips have come in handy to some. I love learning new and different ways to do things to make it easier to stitch.