As others have pointed out, tuning the antenna is not particularly important for receiving. The most important factor for VHF and UHF is the height of the antenna above the nearby terrain. If you simply took the scanner to your roof, along with the rubber antenna, this would give much better reception that having the scanner and antenna in the basement. But since that's generally impractical, the next best way is to put something on the roof.
They're not used too often, but I think the discone antenna would be very good for transmitting, since it served as a tuned antenna for many different frequencies. While it would probably give you some advantage for receiving, it's probably not worth the bother.
I'm a ham, and what I use for transmitting on 2 meters is very simple. I have a PVC mast, which I use mostly to hold up my HF antennas. Pretty much as an afterthought, I wanted to put up something for 2 meter FM. What I did is simply run a piece of coaxial cable to the top. At the top, I unzipped it, so that the braid runs 19 inches in one direction, and the center conductor runs 19 inches in the other direction. I'm sure a "real" antenna would be somewhat more efficient, but this serves my needs. I use it for transmitting on 2 meters, 220 MHz, and 432 MHz, and for receiving on many VHF and UHF frequencies. Since the height is the most critical factor, it does a very good job.
Almost everything you will want to listen to on VHF is vertically polarized--that is, the transmitting antennas are vertical. Therefore, you should also orient this type of antenna vertically. In my case, I simply taped it to the PVC mast.
If you want to tweak it for best reception on one particular frequency, then use the formual 234/F, where F is the frequency in MHz, which will give you the length in feet. In my case, I wanted it to work best on 146 MHz, which gave me 1.6 feet, or 19 inches, which is the length of each leg. But again, for receiving, the length is not critical. Just get it up as high as possible, and as far away as possible from metal objects. If you have an attic, such an antenna inside the attic usually performs well.