I wonder if I have made a perfect wick last time because I have not changed it since end of May, so its nearly 2 months and still works perfectly. Every now and then I empty the tank and burn it at 4.8V and use a jet lighter to clean the wick and mesh, rinse and repeat a couple of times - and it vapes like a fresh wick.
I think I have used 400 mesh for this(but it might be 500) and for coil I used 0.5 kanthal ribbon.
I remember in the past the wicks I made were gunked up rather quickly and I had to re-do the wick and coil almost every week!
It could also be down to the fact that I started mixing my own and adding PG at about 30-40% and I know that it vapes cleaner and leaves less cooked eliquid on the coils.