I am so glad to see so many hand-quilters here. I was beginning to think I was a dinosewer!
I don't mean to offend our machine-quilting sisters, but I want to give gifts that I made by hand, so my quilts are all hand-quilted, hand-embroidered, and almost always hand-pieced. It is the difference from wood sculpture to making a desk with power tools, both beautiful and useful, but different. Both heirlooms, maybe or not, depending on the talent, not the tools. Talent is the main factor.
I think consistency is the key. Parctice making even up and down - the same length onthe top and bottom. start with 2 per inch if you have to. Get that right. Then try 4 per inch and then 6, etc.
As in any other area of expertise, it is technique first, then consistency, then speed.(think ice skating and dance or tiddly-winks.)
I use a tiny needle (8 sharp) a lap hoop (loose like a trampoline) quilting thread run through a beeswax candle, and have practiced for 50 years. I started out with zig-zagging lumps and now can get 10-12 stitches per inch (DEPENDING on the batt) without breaking a sweat. Threading the needle takes me the longest!
I also use thimbles on both middle fingers to help push back and forth from top to bottom. It took some practice. So practice on pillow tops, or pot holders. I bet I made a hundred pot holders when I was a kid! I gave them for gifts.
It is worth the trouble, I think. Tartan was very specific and right on! Good luck.