I have a few things that work for me.
Remember all they can say is no.
I start now asking for permission to hunt woodchucks ( not saying a word about deer) , then in mid summer I ask for permission to hunt deer .
I wear no camo ( not even a hat)
I dress nice ,not like a big shot or a bumb
If from farmers I wear a local seed company hat.
I never ask in the spring planting or fall harvest rush ( unless the feilds are to wet to work)
I try to ask 9:30-11:00 AM or 1:30-4:30 PM ,never at lunch or supper time.
I stop and ask any time I see some one doing yard or garden work.
I carry
permission slips printed out. and give them a coppy with my name, address ,phone # ,truck color and plate #
I tell them I will follow any rules they have ( time of day,day of week and what I can shoot)
I take down notes on rules in a 3 ring note book ,with maps ,permission slips Ect
I also say I will never drive in the feilds or down lanes when wet, ruts in the feild or lane = lose of permission
If you see trash pick it up even if it's not yours
If you get turned down smile and say "I am sorry that I bothered you"
Ask next year ,you never know