Some nice coarse fishing 'legering' tips for you there Mark
I tend to vary the size/weight of the tungsten heads I tie on nymphs, and I often add lead wire as well, to get 3 different weights. A Black marker marks the hook eyes of the heavier ones, but I arrange them by weight in my box (you can feel the heavy ones anyway !).
If you don't tie, and even if you do but need more weight, then the tips Rob and Marc give are excellent.
It is funny, people like Oliver Edwards have a complete aversion to tungsten bead head's on nymphs and hide them in the tying ! Check out FF&FT this month. He argues the fish take these unrealistic "bead heads" out of curiosity rather than as identified food. As much as I admire and respect Ollie, I am not so sure of this......and reading his new book just now, I don't think Bob Wyatt would be either ! That said, OE's flies are about as realistic as you can get, works of art almost.
Lindsay