Here is my small experience about antennas, hope it will be interesting and useful.
I see I will get a lot of messages about that people do a lot of leaf antennas and they work well for them. But I have to note that yes, you can make good one, but that don't means all made antenna will be good as they are very sensitive to small curve change or angle change. Also you have to note that if you have 200mW transmitter and bad antenna which transmits 10% of that - you may have stable video signal on 200 meter range and that will make you think antenna is good till you fly alone. But when there are a lot of transmitters around that will cause a lot of problems for you or other pilots.
Discussion at https://www.rcgroups.com/forums/showthread.php?t=2782965
