I've implemented a few house rules to my game, albeit not because I found ranged attackers to be prevalent (as noted above, a lot of encounters happen at short or immediate melee range). Here are my houserules:
1) damage reduction to armor: medium armor has DR 1 vs bludgeonning, piercing and slashing damage; and heavy armor has DR 2 vs same. Heavy armor also has 5' movement penalty. My game has only human variants so no base speed 20 races are present; base speed is 30 or more. Heavy armor master feat, in addition to giving DR3, now removes the 5' speed penalty. Some monsters and spells with heavy plating or armor bonuses might also have DR. Armor is now more meaningful, especially in a battle vs low-damage mooks. But, I play the intelligent ones mean: they'll swarm the heavy armor tank to pin him to the ground and hit him prone.
2) cantrips have limited daily uses = 2 x # of cantrips known. Canptrips known become cantrips learned, of course. This prevents mages from lighting their way through dungeons with firebolts

Seriously (cause the latter has never been a problem in my games), this is one way that I found to shift my game towards a lower magic environment.
3) spells deal more damage (+ 1/spell level for AoE, +2/spell level for single target).
4) spells that allow a save to end when the spell is cast + every turn of a creature, now allow a save to end when the spell is cast + on the first turn only of the creature. Illusions need to be interacted with to allow a save to disbelieve.
(3) and (4) aim to up the power level of spellcasters, so that they become fearrrrrome
I believe all of our houserules, including these, work well for us. They were not aimed at changing the ranged vs melee power curve, but since they indeed touch on increase heavy (and medium) armor efficiency, and also in limiting cantrip uses, I thought I'd share that we like 'em
Cheers!