Thanks for the tips, I personally found the tips on the food/time ratio thing the most helpful!!
A great spot to use is Stronghold of Security (South of Edgeville/Barb. Village - Level 2; Flesh Crawlers.
Sometimes they can get crowded but on an empty world they're great as the Flesh Crawlers max hit is 1 and have a HP of 25, great for F2Pers that are level 40-80! (I know you've already got the Stronghold of Security already there, I just thought I'd specify a decent spot.)

