Made two different versions that I use both at club and comps - 40mm circular Games Workshop figure bases sprayed fluro orange & weighted with a disc of lead flashing (plus a cycle inner tube bottom layer for grip) for indoor and golf balls drilled & screwed to short tees also sprayed fluro orange for outdoor.
Both work a treat and have never been questioned or commented on by judges & both are dirt cheap as the bits all came from the local charity shop.
A fellow club member makes very flashy 3D printed ones that can double up as ground markers for unsighted bows but that’s a more high tech solution.
If time is super short then two beer bottle tops with nails through the centres joined together with 2 feet of paracord - this setup is placed perpendicularly across the shooting line in front of your toes. Not the prettiest solution but very effective.
Finding this quite amusing as (so far) even after my sighters, and in all conditions, there are an obvious set of size 12 footprints in the ground for me to align to for the next end.
See! Being 300 lbs DOES have advantages after all!!!
Spray talc is good; and very accurate.
You stand as you should then spray across the toes of your shoes and just beyond. When you step away you get two curves in the grass to plant your feet into next time.