Because of the small diameter of the endmills, it can be a challenge to position the mini-hammer on target every time. In this video we used a device called a "SmallRig Magic Arm" used in photography (available from Amazon).
We are using the flexible plastic handle (084A14) and cable assembly with the 086E80 Mini-Hammer:
Be careful not to grip the hammer handle too tight. Just snug enough to maintain position. Position the hammer handle parallel or perpendicular to the endmill with the tip approximately 0.100" from the tool. Pull back on the hammer hammer from below the head (do not touch the head!) about a half an inch and release. If you get double hits, try pulling back a lesser amount or move the tip further away. Once you have it set, repeatable and successful taps are achievable.