Well, I would think that , depending on what you are composting, the compost should be fairly nutrient rich! After all, if you think about it, compost is what mother nature uses. All the plant matter from previous years, falls to the ground, decomposes ,and returns the nutrients to the top soil. Problem is, as gardeners, we cut the stems, and stalks, and remove them from the garden ( which, is a good practice as far as disease control goes), so the "good stuff" is removed . Tree leaves would be a very good source of most of the "trace minerals", and would be a good addition to your compost. And, I would agree that just "watching" your plants gives you a good indication of their needs....yellowish leaves would be an indicator of a need for nitrogen, for example, but for about $25 you can buy your own test kit( usually enough stuff for about 20 "tests") and that will give you a "base-line", or "starting point". Also a good ph test is important, as all the nutrients in the world won't help if the plants can't "eat" them, and the soil ph (potential hydrogen....whether the soil is "acid", or "alkaline") is what allows them to utilize the nutrients. Experiment a little, use some bone meal on some , maybe 10-10-10 on others, and see what works best for your conditions. You mentioned cotton seed meal, and I think that's fairly high in nitrogen ( you would have to google thea to be sure, tho !). I would guess that if you've been adding compost for a while, your soil is fairly nutrient -rich, and will need only "minor adjustments"...Arlyn