Yes, you can (and probably should) meticulously measure your buries the official way (PDF), but once you get the hang of it, splicing by sight is a simple, straightforward process. My “fid” of choice is a simple teflon-covered telephone wire. I find it so much better than a stiff fid (i.e., a thick needle), not only because I can splice thin Dyneema, but I have a flexible eye opening that makes it easy to thread.
I use a basic measuring method for all my buries: 3-4 inches for a locked bramble, fixed eye splice or continuous loop; 4-6 inches for an adjustable splice for a Whoopie Sling. If you’ve ever considered splicing your own Amsteel, give this a try. It really isn’t that difficult.