antennas (aerials) orientation

i consider this subject of extreme importance, hence i bring it here for all to know.
i asked master David T ( http://www.deltang.co.uk/) his opinion. this is what he said:
" Hi. I've done some flight tests with aerial orientations and I've been asked to comment on the 90' thing. Signal strengths are greatest out of and into the sides of aerials. So the Tx aerial should be 'side on' to the model. Personally I find horizonal easiest.
The Rx aerials receive strongest signals when they are 'side on' to the incoming signal. So orientate and place them where that is most likely. If you have two or more you can maximise coverage by using different positions in the model and different angles relative to each other. The model keeps changing orientation in flight so I guess this is where the 90' idea comes from.
Signal strength reduces over distance so if you fly gliders very high you probably want the Rx aerials horizontal to the ground at the bottom of the model to get most exposure to signals.
I believe signals reflecting off the ground cause problems for radios at low alititude. Coming in to land at low altitude towards you from a long way off is probably quite challenging for radios. If your Tx aerial is horizontal then at least one Rx aerial probably should be too. Having that aerial behind a big lipo or engine won't help!
So as already mentioned, there is no perfect layout. The objective is simple though. You want Tx and Rx aerials parallel as much as possible and this is more important in the difficult scenarios I've mentioned.
Regards, David".
(just in case: when he says 90' he means 90 degrees)