Not sure if any or all of this has been posted before, I’d like to think I’m not reinventing the wheel but hey, there might be a few good ideas here that help and some have saved me a LOT of trouble. This board has been invaluable with help so thought I’d try to contribute.
If I’m doing something that isn’t mission critical regarding measurements - meaning I can fudge it a little in either direction for depth - one can save carving time by adjusting either the depth of the tool cuts or the overall depth on the item. For example:
You have a project with cuts that will be a depth of .1". Your X-Carve is set to .028" per pass. That’s going to be four times. One could adjust the depth to .099 and the X-Carve depth to .033, which is close enough that it should work fine but it saves you an entire pass. Depending on the size of your project this could be a HUGE time saver. I’m not advocating changing your tool depth to .1 per pass or anything, but a small increase hasn’t caused me any issues. Basic rule of thumb I always heard was half the width of your bit anyways.
Speaking of fudging, I’ve also lied to the Easel software about the size of my bit when I had a project that wasn’t super critical but the lack of a cut would look weirder than a slightly thicker one. I wouldn’t do this on parts that have to fit together, but if you’re carving a piece of art, sometimes entering the size of the bit as say .10 instead of .125 will make something carvable and still presentable without having to go to a .0625 bit and waiting a lot longer for the project to finish.
I’ve also had to drill simple holes in stuff before and used the X Y Z controls that come up when you start to carve a new project as a manual drill press. For me it’s a lot easier than measuring, drawing out the project, etc. I can at least do my pilot holes like this then come back with a hand drill.
You can stack tabs on each other to cut down on the number of them on a project - sometimes I have had items I was carving that four tabs didn’t make sense, so I pulled one on top of the other. I also like adjusting the height and length of the tabs as needed, usually you can get away with much smaller ones. It’s a fine line, but smaller tabs especially on a curved edge are a lot easier to deal with when you’re sanding them off.
For most substrates when I’m setting the Z height to touch the surface of the item, I’ll either put a piece of paper underneath and go down in .01" increments until it touches the paper (meaning I can’t move it) or I’ll actually turn the spindle on, and I can usually hear the bit when it first cuts into the wood.
If you can, don’t put a clamp near your X and Y 0.0 coordinates because if there is a problem with the carve and you cancel it, the spindle may cut into the XY=00 clamp on it’s return and just add more mayhem. Don’t ask me how I know this. 
Oh, and advice from my dear departed father long ago - Measure twice, cut once!
