I thought I would try to pass on some info and experiences. I used to be a Ham that only had an HT . . I wanted to do things that my rubber duck would not allow such as get on repeaters that were not really close to the house, volunteer for activities, etc., but I was limited to an HT for a period of time in my ham career. I found that different antennas can make all the difference in the world with an HT. So I’ll try and describe my experience with a few of them.
Tiger tail: You can google this but it’s a short piece of wire added along with your stock rubber dicky or other whip attached to the HT. I never was able to measure a difference so I would say don’t waste your time on this one. Others may have had better luck so your mileage may vary.
Slim Jim: I LOVE LOVE LOVE these antennas. Info on what they are here: http://www.n9tax.com/slim%20jim%20info.html You can buy one from this guy with 16 feet of coax attached for about $26 including whatever connector you need for your radio. I have a couple sitting along side my HT’s right now. I used to sit on my deck outside, and hang one of these from a nail on the gutter of my house. It is 1000% better than the rubber ducky on the HT. You can take one to an event and hoist it up a tree, put it on a painters pole. There are a ton of ways to get one of these in the air. The other thing I really like about these is they are DUAL Band! 2m AND 70cm. The others below are single band.
Ground Plane: When I first was licensed in 1995 I only had an HT. I made one of these out of a SO-239 and wire coat hangers. That’s pretty cheap right? I put it up on a pole next to my house, ran coax down the pole in a window and was able to reach local repeaters sitting in my Lazy Boy with my 2 meter HT.
J-Pole: You probably have heard of these but I have never made one. So while I don’t have experience with them, I know people that have and they work.
At the end of the day, if you have an HT and want to try something other than your stock rubber duck, there are a lot of options out there that are either easy to make or fairly inexpensive to buy. If you want to make one and need help, there are plenty of elmers available that would be happy to help, me included.