RE: Engine runs on the flight stand?
Stake in the ground. 5/16" nylon rope tied to stake. Other end looped under horizontal stab., over fuselage ahead of vertical stab and then back under the other horizontal stab and tied to stake or itself WELL. Pull it up snug before starting engine (this is important).
I use a stainless steel Swiss Army Bayonet for a stake. Gets some stares but I never have to argue over a spot in the pits.