Hand held uually means the person can move it around to ANY position/orientation. That means that you can end up with corss polarized antennas for transmit and receive. So if you made your transmitter antenna to be dual or circular polarized, and the receive antenna was one polarization, you could remove that 15 dB or so of cross polarization loss that you have to make up for in system gain. You do take a 3 dB loss off of the best system gain you could have with that approach.
Try an experiment...go out to maximum range and rotate your hand held device so that you go through co and cross polarization. See if holding at certain rotations gives you much greater range than other orientations.
Another issue...it is hard to get omnidirectional coverage in a hand-held device. This is because your hand will change the antenna radiation pattern. Also, the electronics on the PC board will also change the antenna's radiation pattern. So 2 antennas with different radiation pattern orientations might help too.
Give us more info, is the hand-held device receive-only? How big?