I wanted something that was heavy enough that the quadcopter wouldn't blow it around, but portable enough that I could take it with me on any trips.
I used a kitchen floormat (the soft/rubbery type) and then spray painted the 'H' and outline. I can roll this up and then use a strap to keep it rolled up and also attach it to a backpack:
I used a bit of ply wood and put some rubber feet on it so it would stabilize better off the ground and then stuck a sheet of corflute you no the stuff the use for signs https://www.google.com/search?q= ... A&biw=1920&bih=1106 I stuck it to the plywood for a a smooth landing and of course masked off and sprayed a fluro pink H so it can been seen easy from height.
I use a simple DIY disk cut out of rigid foam (about 37 cm in diameter). It's waterproof, light (but heavy enough to stay in place in the wind), and clips on to my backpack.