I've found that often, there is more material left in the tubes than what you get when you buy the little 2-tube epoxy packs from the hardware store for... (I'm not even sure what they cost anymore, it's been so long) $5?
Admittedly, most people will buy those packs and use, at most, maybe a chocolate chip's worth of each at a time for what their needs are. Well, let me tell you some of the things possible if you have several tablespoons worth available.
Remember that most epoxies of this type are usually mixed in a 1:1 ratio. 1 small blob of part A and an equal size blob of B. Many of them come in (2) different colors for each part so mix them until you have a uniform color with no streaks of one or the other.
Also remember that once they're mixed, you've started down the road of no return...you need to use it because it can't be stored for use later...