I don't wait til the end of a project to weave in my tails.
Ack! I take my 'medicine' one teaspoon at a time!
I usually take a CHIBI yarn needle and weave the tails in.
TIP: if you are using wool or a wool blend...NO TAILS are ever necessary. Join a new ball of yarn using the felted join, or the Russian join.
If you have tails due to color changes at the ends of the rows...felted joins will be tricky. But do-able.
I avoid 'tying' in new skeins like the plague!