Because it is nutritionally complete and amazingly lacking in stuff you don’t need, you’ve got some wiggle room to spruce up the mix a little. Remember that it might seem counterproductive if you’re looking at the numbers compared to official Soylent, but it is still vastly superior to regular eating habits.
I often make mine with cold-brewed coffee and a shot of heavy whipping cream, that alone is enough to make the shift from tolerable to enjoyable. I also like to add Nesquik sometimes, it has its own kind of graininess that blends right in with that of the Soylent. The other day I tried it with a banana and a big fat scoop of peanut butter, and it was wonderful. I think the peanut butter does something to smooth out the texture.
I’m now compiling “fixer upper” recipes like this so that I can prepare different varieties and break up the monotony of plain Soylent. My next experiments will be strawberry Nesquik and hazelnut coffee creamer.