So how do you store DMT in a way that it could be very easily consumed and taken to the metal mesh of a machine?

I believe it has to be some small glass bottle? But what kind of a bottle has a small enough neck so that only several pebbles of DMT would come out at once?

Any ideas where to get such bottle or maybe how to make one myself?

Go to your favorite popular auction site and search for "small glass vial"

I use amber colored 5/8 dram ones with a screw on lid personally.

The other thing you might want to consider is buying like 6 of them (they are dirt cheap) and pre-filling them with however much spice you usually dose. That way there is no need to be weighing out doses in between trips.

Obviously don't get caught with multiple vials as this will very likely get you an intent to distribute charge.

5ml brown glass vial for 1g of freebase and a 10ml wide neck vial for 2g of infused herb. Perfect.

I just got 10 of these online for pocket change. 5/8 dram I think is the perfect size.

Milligram scoops. Amazon, or supplement store.

One of my favorite sites: Specialty Bottle

I personally put all my smokable spice in capsules. I put about 30mg per capsule as that is about the amount I like to put in the GVG. Convenient and allows me to reliably and quickly pour out a pre measured amount. Just make sure your spice is really dry when you put it in the capsule else it some of the grains may stick to the gelatin making your dose incomplete.