So lets be honest. Long Bows are easily one of the top notch bows in the aesthetically pleasing scale, but they're such a base weapon that they sometimes arent worth using. I'm trying to figure out the best way to make them the most damaging without having this enchantment glow which wrecks the effect of a simply weapon. I thought about smithing it as high as I could with enchanted armor suit of smithing AND a good potion to increase my skill, but is there anything else I could do? Drain Health would add more damage to the target, but that makes the bow glow this silly red.... any tips or recommendatios?

As far as i know, smithing and enchanting are the only real way to make a weapons stronger. If you are on PC i guess you could find a mod that had a strong bow that looks like a long-bow or you could go into the creation kit and change the power of the bow their (though then all longbows would be that strong on all files) There are some mods that allow you to ask a blacksmith to smith/reinforce weapons and armor f you do not want to level smithing.

there is no set max damage...

if you use the Fortify Restoration loop, you could potentially have a Long Bow that does enough damage to one-shot any Dragon.
but hey, whats the fun in that?

Glitches aren't fun.

I'd say upgrading that bow to the max, including all the Fortify Smithing stuff you can get.

Or just mod the hell out of it, if you're on PC.

You can enchant gear to fortify archery, thus increasing the bow's damage outpout.

True but the longbow still doesn't make any sense because deadric ebony etc will still do more damage with this gear so there's no point in using the longbow objectively unless you gimp yourself

This is one of things i dislike in Skyrim , the vast difference in damage between type of materials , ideally all bows should do more or less the same damage with slight differences at best so that your skill is the biggest factor

for instance i find the iron weapon and armor really nice , especially with the amidianborn book of silence mod that improves the vanila textures , so i tried to use those blacksmith elixirs to boost my smithing when improving iron to make it as close as possible to steel and better materials

But in the end , i found only the restoration glitch can even out weapons damage if you use it moderately , so that iron and steel stuffs won't become totally useless after 4 hours of play

Not on PC... Ecksbawx over here.

True shot potions may work too, but I was hoping to keep all the damage output worked up in the bow. Good recommendations for expanding my solution pool. Any others?

Yeah, there is a set max damage actually. It's related to some coding limitations that stop the value somewhere in the tens of millions I think, afterwards it resets to a negative value. For all intents and purposes though, you are right.

If you don't want to use the restoration glitch , maybe try to save the blacksmith potions and gear (that you can buy if you didn't invest in enchanting ) only for your longbow so that its damage will be closer to other bows