1) Cleanmem program. You can set it up and then use Task scheduler to tell it to run every 5 minutes. This dumps excess information from the client which helps bandaid the problem.
2) NTCore made a "64 bit patch" which tricks windows into assigning more memory to a program. Allowing Rom to use more than the normal 32 bit limit, which can help.
These two things help a lot, however the main problem with crashes comes from the memory leaks associated with the graphics textures. Lower settings, the longer it takes to crash. I have been for the last 3 weeks playing with the settings to find a group of settings that will reduce crashes to a minimum while affecting the "prettiness" in game the least. Here is the list that I did:
1) Lightmap Resolution- lowest
2) Shadow details - 0
3) Sky Detail- 0
4) Water reflection off
5) Water Refractions off
These are some things that (while your computer can completely handle them) are a lot of things loaded every time you are in a new area, etc etc, causing the memory leak to hit critical mass faster and crash. This then should allow you to keep your resolution high, character detail/terrain detail/etc all at the levels you like and should help reduce the memory leak and allow Cleanmem and NTCore to try to pick up the slack.
I do still crash but a lot less often. I could run at 800x600 with medium to low graphics all day and it not crash.. but what is the point of that