My experimenting might have to wait until next year now. But I'd be really interested in seeing some pics of your antenna.
At the risk of serving as a 'good example of a bad example', pic is attached. This is literally some scrap 14 AWG romex I had, and a scrap piece of crown molding. I 3D printed some 'bow ties' to hold the three points where the elements come together (but don't actually touch) and provide attachment points. But I'm not going to climb through the blown fiberglass to get a pic of the backside, so my annotated pic will have to do!
This is a pretty minimal / crappy example, but with digital, you either have it or you don't and this brings in all channels I can reasonably expect to get with perfect clarity - so not really a need for anything more unless I want to get crazy and try for a third copy of PBS from a station 90 miles away.
Even within this design improvements could be made though. Adding a back reflector can help gain in the 'forward' direction at the expense of cutting down on signals from the rear. Adding NAROD elements is supposed to help gain as well.
You can also see my 'signal booster' attached on the rafter support at the right. This isn't so much to boost a crappy signal, more to make sure the decent signal I get has enough strength to propagate down the coax to the basement, through the distribution network and in some cases, back upstairs to the TV.
Yes, ideally the antenna is made to the wavelength. What I really meant was I want to see if moving the antenna or making a change would help with the particular station I've been having trouble with since some kind of change they made. I may have an old Radio Shack amp I could try, but if I recall last time it didn't help. The station I'm having trouble with is UHF, channel 30. I also used to know the formula for antennas, half wave, quarter wave etc., but it's also been a long time for me since my ham radio days.
You will really have to bring together several considerations for getting 'trouble' channels. I'd first go to one of the many station/antenna tracking sites.
https://www.fcc.gov/media/engineering/dtvmaps for example, see if it is even possible to get the channel. There might be a mountain or other topography which will make it nearly impossible or require a multi-hundred foot mast.
Next you have to match the antenna, not only in wavelength, but also style... in the middle of a metro area, an omni directional might be a good choice to pull in strong stations from all around. Just outside a metro area, the Gray Hoverman might be a good option to add some directionality, but still have a wide main reception lobe on the front face for medium strong stations. If you're far away, the yagi - especially with a high number of elements would give the highest gain, but you'll need to have it pointed like a laser beam at that one station and good luck picking up much else outside the 'main lobe'. This is where an 'antenna rotator' comes in handy. Or I guess you could always have a farm of 5-6+ yagi's pointed at various locations on the compass.