Some equipment types can seem a bit underwhelming. If you find the players are always selecting the same weapons, it might be time to shake things up a little.
Particularly in AD&D/OSRIC and similar.
I've examined a few below:
Crossbows are potent weapons, or at least they would be, if the base damage wasn't so low.
Using the weapons vs armour tables in AD&D 1st edition remedies this some, but with their slow rate of fire, they're just no match for an archer in most cases.
My suggestion is that crossbows ignore the AC bonus from using a shield, and may reroll any damage dice that score a 1.
Shields giving +1 AC is a tradition that goes back to the original game, but some players may feel disappointed that the shield only provides a 5% difference in the chance of being hit. Particularly if the campaign uses two weapon fighting, the humble shield seems a far worse option.
Magical shields can help remedy this significantly, but if you need a little extra, simply give shields an extra +1 AC against ranged attacks. (if combined with the above crossbow rule, shields would be +1 vs crossbows and +2 vs bows, slings and so forth)
I don't remember when I last saw a player using a spear. If you want to encourage their use a little more, a simple rule to take into account the extended reach of the spear is to give enemies a -1 penalty to hit a spear-wielder, in any rounds where they were hit by the spear.
As written, there's not much reason to take a warhammer over a mace. To emphasize the armour piercing abilities of the hammer, give it a +1 bonus to hit against any enemies wearing rigid armour (banded/splint or better, and monster equivalents)