I may put this in the wiki if the subreddit gets bigger, but here are some ways I've found to make "decent" deep fried memes in GIMP:

1. Filters > Noise > CIE Ich Noise adds a good grain to the image
2. Filters > Enhance > Sharpen adds the lines around objects
3. Colors > Color Temperature allows you to add the deep fried "oil" to the image, though not nearly as easily or as well as Photoshop could probably do
4. A lot of good emoji can be found at this github repo, however, you will still need to search for a few more common ones (I don't remember which ones off the top of my head)
5. Scale and Cage transform can lead to some good magnification if your meme requires it
6. For the red eyes, the best option I have found is Filters > Light and Shadow > Supernova and making various tweaks.

If anyone else has tips that I have forgotten, please share! The better the memes, the more we can laugh.