Having been a combat engineer and dealing with explosives of all types, the making of improvised explosive devices is something with which I have some familiarity.
We used to receive training and give training on the use of conventional explosives — to blow up bridges, fortifications, airfields, buildings as part of the mission to aid the mobility of the friendlies and to impede the mobility of the enemy. Typical combat engineer stuff.
We also used to receive and give training on the construction of “improvised” explosive devices.
We used to learn all about the explosive chain :
1. The charge (the explosive);
2. The initiator (the fuse or blasting cap);
3. The activator (what activates the initiator);
4. The power source (what activates the activator); and,
5. The container (what contains the finished assembly)
In addition, you may add something to the device, such as nails or bolts, to injure the victims.