I always start by making sure my favorite flies are well stocked in the boxes. If the flies from the past season are tattered, then they get dumped but some of them only need to be repaired.
The PT Nymph was again one of the best producers esp of brook trout. This one got a new tail, some added PT to the body, another round of herl and new shell back with legs.
This year I am adding a translucent back which should reflect some light. It is made from "UV Knot Sense"
I'm also stacking them loosely in a fly box I inherited from my long departed dad who is fully responsible for my addiction. It is a Cortland box and must be 60 years old or more. I find the tails get easily damaged any other way.
Of course Mayfly nymphs only have three tails but you are better off to start with five. There will be three soon enough!