How to neutralize flight? (levels 4-7)

[Calybos1]

I've got a few characters in the level 4-7 range who are encountering more and more enemies that fly.

What are some recommended ways for a level 4-7 party to bring down a flyer? Note that I'm not looking for items or spells that will let us fly up to him--I want to bring HIM down to US.

Any suggestions?

[MC Templar]

nets, bolos, tanglefoot bags, called shot rules, command spells, hold monster spells, retreating to areas with lower ceilings, enlarge person on a guy with a polearm (or a mancatcher).

[Owly]

I emphasize the readied action. Players often overlook this in their excitement to utilize their initiative.

Also consider a magic-user who summons an air elemental or two to harry and harass the flying opponent, preventing them from performing flying maneuvers, or tempting them to come closer.

Obscuring Mist/Fog is also handy, as is Protection from Arrows and Protection from Energy, depending on how those enemies are utilizing their flight advantage.

Of course, there is the old adage of "always get your opponent to fight the battle on YOUR terms", i.e., fall back to an area where their flight advantage is neutralized.

[Lincoln Hills]

I'm not sure how many people have done this, but a PC I knew tended to have his wizard cast web in the upper half of high-ceilinged areas with flyers in 'em, to force them to occupy the 0-10' altitude that we could engage them in. Not all rooms are the right height or size for that, obviously...

[Rerednaw]

Too many variables.
But that aside...in addition to the above.

Smokesticks. 10 gold for concealment is a pretty good deal.
Tiny Hut spell. Total concealment.
If there's cover (trees) nearby, run to them.
Ranged evocation of course works. Ball Lightning (Flaming Sphere's bigger brother) is one to consider.

Summoners can spam summons.

With the readied action (cast when flyer is in range), even something as lowly as the Command spell ("Fall!") can be quite effective.
Sound Burst stuns if the targets fail their fort save. That usually means a flyer will fall.

[Whisperknives]

This exact situation is why people stopped laughing at my fighter who carried a harpoon.

[strayshift]

Archers, low ceilings, incorporeal undead (who could take the opportunity for some 1-1 with said caster), ranged grapple type weapons like the aforementioned harpoon, reduce visibility - as has been said before, etc.

If you want to shake them out of complacency once in a while, I would emphasise that nothing says 'I'm a mage' quite like flying around combats casting spells ad word will get out amongst the bad guy/adventuring communities. If your enemy have the chance to do their homework they may prepare some special surprises if they have the resources all it takes is another mid-level spell user or some potions(e.g. an invisible, flying, rogue for example).