Sometimes I leave the needle in the fabric, turn the fabric 180 degrees and take 3 or 4 stitches right on top of the seam. Only works with smaller pieces, a large piece is too hard to get turned around...
most often, I pull the bobbin thread up to the top and tie it off.

I pull the front thread through to the back giving the two strands on one side of the fabric. Then I use a surgeon's knot. Twice. Usually the knot won't show. (Surgeon's knot is like the first knot you tie in a shoelace, only instead of going through the first cross over once, go through twice. Clear as mud?)

This is the best idea. But I'm too lazy to move the lever. I have reverse, just too lazy to use it. When I was learning in the 70s, no one backstitched. Or maybe I was lazy even then and didn't go along. But my method of hand sewing the thread tails is not indicative of laziness. But that's only when I don't want the thread ends to show at all. And I knot the thread, which is harder than reverse. Maybe it's this -- I don't like to take my eyes off the work to fiddle with the lever, so when I do reverse I end up pushing the lever all the way up and get teeny tiny reverse stitches. I have screw stops on the end of the levers to prevent this, but I don't want to jam that screw into my perfect-looking vintage stitch regulator plates. (Vanity, laziness -- none of it is good!)

actually I think my main problem with reverse is I feel that on light to medium fabrics it's not good to stitch 3 times (forward, back, then forward again). Too much stress on the fabric or too many holes or something. I don't know -- this could be a lame justification for laziness and vanity.

There are a lot of methods to back tack your stitching. My favorite is this: When I start a stitch I hold the top and bobbin thread so it will not wad up underneath, then after three or four stitches I stop, raise the needle, raise the foot and pull the fabric forward about 3 stitches worth, then lower the foot and start sewing again. Makes a very nice back tack. At the end of the seam I do it again.
Does the same thing as using reverse or a back tack setting.

When doing decorative stitching I use a hand sewing needle and pull the top thread to the back and hand tie them off. This is because many machines will not back tack properly when using cams or other types of stretch stitches.

I grew up watching my mother and later my wife sew. They always back tacked the start and finish of seams. Not doing so seems strange to me as I've had lots of seams come unstitched if not back tacked.

Joe

I too lift the pressure foot and pull the fabric forward 2 or 3 stitches worth :)

When I treadle I just stitch about a 1/2 inch or so, lift presser foot, pull fabric forward and start stitching again over the first 1/2 inch or so stitches. Holds wonderfully.

Sometimes, I lift the foot and turn it around and take a couple of stitches - lazy way.

Long, long, long ago, when I was a child learning on my mother's sewing machine that didn't have a reverse, I also was taught to leave the needle in and turn the fabric and stitch a few stitches. Mom was a home-ec teacher.

My oldest machines just have a knob for the stitch length, so I don't change the stitch length if I don't have to, so turning the fabric works for me.