Using just your hands is a effective and easy way to call moose. Lots of good videos and tutorials on youtube and others sites that give good instruction and guidance on how to do it. You can learn both cow and bull calls and can use both to help you on the hunt. I would definitely practice before the season starts. There are calls that you can buy, I have never bought or tried any of those, but i would imagine they will work. I never thought to try and build my own call like some of the others guys that posted on this thread, which is pretty ingenious and I bet fun and challenging as well.
What ever calling method you end up using ensure that your in a position to be able to take the shot if a moose responds. The first time I tried calling, I was pretty skeptical and didn't thing that anything would respond. Boy was I wrong, I had a 40 plus inch bull come running in from over 500 yards, he came in so fast that me and my brother were scrambling to try and get set up and ended up scaring him away. My 5 day hunt was in Utah in late October with hot weather, we ended up seeing 40 moose, 5 of which were bulls. Calling brought in 4 of the bulls and 15 cows, just wasn't able to get the shot I wanted on the bigger bulls and ended up taking a 5 year old bull on the last day that came into to me calling at less the 200 yards. I did find that calling around water be it a pond, creek, river or lake seemed to help me when calling in moose. Calling in a bull moose to me is even more exciting then having a bugling bull elk coming into your call. I am eagerly waiting when I can draw in Wyoming, Idaho or other states I am applying for moose in. I think that with a little bit of practice you can be effective at calling moose during your upcoming hunt, just don't be afraid to try it or use more the one method of calling.