Do you have a favorite type of concentrate to load with? It seems waxes or shatters work best - I tried a heavy oil and ended up making quite the mess!
I don't ever have waxes, as I see no point in making my already stable oil into something that degrades
but that's a topic for discussion elsewhere
hehehe
As for my oil, I load oil that would be considered shatter or sap, or heavy oil, depending on the temperature. Out and about, at this time of year, I could put a parchment paper fold of oil in my pocket, sit down, take it back out, and it would be a pile of small chunks and dust. Same oil back in side the house, etc, and it is a sap, or even semi viscous heavy oil. I've found that when properly purged, every bit of oil I've made and consumed over the past year ish has been just oil; a shatter at cool temps, sap at room temps, and heavy thick liquid at hot temps...
The ghost pen seems to take whatever I throw at it, but as for ease of loading, I find that a dab of shatter or sap is easier to get to stick onto the coil, and not stretch out/make a mess with. When my oil gets too warm, it can be less than easy to work with.
I usually get a chunk on my finger, and pulse the heater once, then set the chunk onto the heater, holding it in place for a second, then I carefully quickly snap my finger or dabber away from the dab. With a quick pull, it doesn't seem to pull on the dab/coil, yet just disconnect from them. I think most of my mess issues come with an oil that is less than solid and stable, and me pulling my finger or dabber away too fast.
After it's on the coil, I pulse the heat for a second or less on, then several seconds off, until the oil is melted into the wick/coil significantly enough to keep it from being pulled up into the mouthpiece or falling down into the bottom of the cup.
So yeah, you're probably on the right track with waxes and shatters!