3. A decent thread makes ALL the difference. If you're stopping every three stitches to undo knots, the time you take to EPP will double. I use Aurifil 50wt in cream. In my experience a lighter colour thread will tangle less than a darker colour thread which I guess has something to do with the amount of dye applied to the thread. You might prefer to switch to a darker thread if using darker fabrics but I quite like the look of the stitches - since I'm taking the time to hand sew, I may as well shout about it.
4. To minimise knots, thread the needle from the end of the thread that comes off the spool so that the knotted end is the one that was the closest to the spool. Once threaded, run the thread through your fingers two or three times to reduce twisting. Some people use wax or thread conditioner - I don't find I need them if using Aurifil.
6. Sew fewer stitches per inch. Around internetland, I've read how many stitches people use per inch and they use waaay more than me. I sew at a rate of about 6 stitches per inch. If you squint at this photo, you can see the number of stitches I use - each side of these lozenges is 1 1/2" long. It looks nice and neat and it holds well.
6. The rest of what I do in EPP may or may not be faster than anyone else. I make my own templates printed off the home printer rather than buying templates. I pin my templates rather than gluing them. I stitch baste them through the paper rather than gluing or stitching not through the paper. I remove the paper templates by unpicking the basting stitches using the blunt end of a needle. I re-use papers. All personal taste and no slower or faster than any other method I don't think. Oh and I like to EPP in the courtyard off my kitchen where my husband and twin girls were sat last night reading their books with a nice glass of something. I've just noticed my husband has come home from work, changed into shorts and left his socks on. How very British (he's Welsh so this comment will wind him up).