3. roll up herbal joints
4. use a dropper to carefully drop a measured dose of DMT onto each joint
This is not really ideal.
I mean, why drop drops onto already rolled joints, Its much more easy and practical if you measure out say 1 gram of DMT and 1 gram of caapi leaf, then you know that you have 2 grams of 50%DMT so in other words, if you want a break through dose of say 50mg or so, you smoke 100mg of material.
And of course, if you want it in a joint, you simply mix the 100mg of material (containing 50mg of DMT) with whatever herb you want to mix it with as you roll the joint, you still know what dose your getting because you simply know that the mix is 50%/50% (before adding other herbs / weed to fill the joint)
As for the shotglass collecting DMT on its sides, I use something more like a dish than a shot glass, but the technique goes through to any vessel. When you get down to the end of drying it simply continue mixing the plant material every few minutes or so until its dry. this way it keeps pretty much all the DMT in the plant material, of course there is left over residue on the shot glass, but its not like milligram upon milligram.
I would like to note at this time that While its incredibly fun to smoke joints of changa, its incredibly wasteful and the experience is far from the same experience if you smoke your dose all in one hit (or really quickly in general) like when smoking FB spice.