It may be hereditary. Mine are, so I'm always going to have teeny fat pads under my eyes. What sucks is that they're sensitive too, so if I cry, drink a lot, or eat a ton of salty food my face BLOWS up.
Like I said, since mine are permanent unless they swell do to outside factors, I don't mind them much. But if I know I'm going out the next day, or have an event coming up, I try to abide by my lil 'checklist:'
-Avoid salty foods/adding salt to foods, most importantly after 6pm
-Avoid excessive alcohol/caffeine intake
-never using undereye creams or lotion under my eyes
-sleep with an extra pillow so my head is a bit elevated
-remove ALL eye makeup before bed! so so important, if I don't my eyes swell so bad
-stay hydrated
-try not to cry haha
hmm that's all I can think of so far, but I hope it helps! Sometimes when I follow all my rules I STILL get swelling. In that case, I keep a gel eye mask in the fridge and put that on for 10 minutes. Following that, I'll jog for a bit and that seems to help too, though I'm not sure why. Also, if you're in a real bind, you might try natural diuretics. I'll eat foods high in potassium (like bananas) since they help alleviate bloating.
hth! I def have to get some cooling Prep H now, haven't tried that one yet...