Light loads - no problem (so long as you don't come back at me if something goes wrong)
I started-out like you; wanted light loads for a .303 and went down as low as 2.5 gr of 2400 - they didn't work too well and left the chamber full of unburnt powder; made an awful mess. At least they always shoved the bullet out the end of the barrel - I shudder to think what would've happened if they didn't.
In general, the lower the velocity, the faster the powder you want - the heavier, slower powders won't generate enough pressure to ignite, and they'll fill your cylinder and barrel with crud. A suggestion here is handloads(dot)com - they have lotsa loads from lotsa people, a lot of which aren't found in the manuals.
An example - my range load for .357 is 3.3gr Titewad behind a 125gr LRN (lead round nose) Lee bullet sized to .358.
CAUTION - Titewad is a very fast shotgun powder; Hodgdon does not even list it as a pistol powder, and I only started using it out of desperation because it was the only powder I could get at the time. DO NOT go any heavier on this powder - the gun you save may be your own! The Vihtavuori site (great site) lists Titewad as the fastest powder of all, and when I started working up loads, I went as low as 2.5gr (in .38 Spl cases). 3.3gr is just what I'm looking for; mild, quiet, clean, works well in 9mm and .38 with light, small lead bullets and no signs of overpressure.
{ - Incidentally, you DO know the signs of overpressure? LEARN THESE before you start experimenting! - }
And it all appears to burn - no crud left behind, which is an issue in revolvers with great big cases, itty little powder loads and the flash gap bleeding-off the pressure so the powder doesn't get hot enough to burn. I initially settled-on 3.2gr but my Hi-Power was shooting atrociously; wide spread, yeah I hit the target but that was about it. Then I noticed that one or two bullets of every string would keyhole; which means it went through the target sideways-on, so the bullet is not spinning fast enough to stabilise, and it wobbles once it leaves the muzzle. Only one way to spin the bullet faster - drive it down the barrel faster. I added - literally - one tenth of a grain, bringing the load up to 3.3gr - and the Hi-Power started shooting like a champ.
AGAIN,
CAUTION - Titewad gave me the only failed case I've ever had; I loaded-up some 9mm 147gr Speer JTC's with this powder load; all but one shot normally, but one of them blew-out the primer and peeled-back a chunk of the case wall. I'm playing with fire here - that bullet was 'WAY too heavy for a fast powder like that - if it were me, I'd use that load (or any fast powder; Bullseye, Vihtavuori N310, Red Dot &c) ONLY in the .357 and ONLY with 125gr-ish lubed lead bullets; DON'T use Titewad in your .44 with heavier bullets. Indeed, don't use my load-data at all, please... "DISCLAIMER- This load data is posted for comparison purposes only, etc etc etc..."
My go-to load for .45 ACP is 3.3 - 3.6gr VV N310 with a 200 - 230gr lead bullet; but VV N310 doesn't meter all that well in the slide bar on the Dillon Square Deal - Titewad is dead-nuts consistent out of that slide bar.
If you want to work with light - mid-range loads, consider Trail Boss. It advertises itself as optimised for mid-range lead loads, cowboy action shooting and the like. Again, 3.6gr is what I worked-up to; and Trail Boss is so big you'll have a hard time putting a double-load in anything. I don't use Trail Boss anymore, it's dirty, but I used a lot of it. For heavier, you might move into the second tier of speed, VV N320, Unique etc; but you'll need more of it, or it won't burn well in a revolver.
I recently worked-up Win 231 for .45 ACP; started at 3.2gr, which was no good - action wouldn't cycle. I ended-up at 3.6gr, which would cycle, but over the space of ~70 rds it made a gummy mess of the gun and mag's; I ultimately took it up to 4.2gr, which was better; but then I said "heck with it", went out, bought some more VV N310 and I'm selling the rest of the 231 - don't like using that much fast powder. I'm told it's the kitten's spats in 9mm, but I have a 9mm load I like already and I couldn't be bothered working-up 231 loads for 9mm.
But to carry-on the 231 story, I had ~40 rds loaded with 3.2 and 3.4gr of 231, that wouldn't cycle a .45 - how to burn them off without having to pull all those bullets, empty the cases, and so on, and so on... Simple - just put the shaved cylinder in the Webley! So I did that - and you'd've thought I was shooting shot out if it; so much unburned powder spraying out the muzzle, it looked like it was raining! Dirty mess to clean too.
In sum, read the manuals, don't be afraid to try-out new stuff, but err on the side of caution - especially with fast powders!