Reddit reviews Modern Tea Filter Bags, Disposable Tea Infuser, Size 2, Set of 100 Filters - Heat Sealable, Natural, Easy to Use Anywhere, No Cleanup – Perfect for Teas, Coffee & Herbs - from Magic Teafit

Ok, I was a barista for 4 years at a traditional coffee shop and I have a hunch as to why you had trouble. If you're grinding the beans very fine and packing as much in there as the bag will hold, you're actually going to get a weaker brew because the water isn't able to effectively circulate through the coffee, even if all the grounds are wet. Grind it a bit coarser and leave room in the bag for the grounds to expand. A medium/coarse grind would probably work best, just let it steep a bit longer.

Edit: I realized that a lot of bags available really are too small to hold enough coffee, here is a link for bags that are big enough to get a good cup but honestly, I'd still use the reusable basket.

When I do bring a stove, I use T-Sac Filter Bags. As far as a mug, I use an Evernew 400ml mug that fits inside of am Evernew .9L non-stick pot. This allows you to create one or two servings. Hope this helps.

I would keep it as whole as possible just because that's the logic I use for tea, if its not strong enough grinding may make it stronger but may introduce off tastes like bitter or grassy. This may not be a problem for you with your specific taste, but I would give it a try whole if only because its easier and then experiment with a finer grind.

I like these for bags

https://www.amazon.com/T-Sac-Filter-Bags-Disposable-Infuser/dp/B010RV810W/ref=sr_1_1?ie=UTF8&qid=1493325561&sr=8-1&keywords=loose+leaf+tea+bags

(Look at the sizes and get one that meets your needs as they go from small cup to pitcher) but often just use a stainless steel strainer which can be found n amazon for a similar price.

Today I processed assorted shake and trim. Used approximately 5 grams inside of T-sac filter bags. Pressed at 196F for 3 minutes.

On previous presses, I had the temp closer to 220F and it came out way too green and dark. The T-sac hemp filter bags are pretty versatile and I don't have to worry about stray synthetic fibers as with micron bags. I fold up a pouch, cut away the excess filter, and go to town.

The product is still dark, but tasty. You won't get an intense head rush off these dabs. Instead, its a stoney and sedating creeper that sets in after a few minutes.

O-Cha's Chiran is my favorite Japanese daily drinker, and we'll priced. $15USD for 100g is equivalent to fifty teabags. In fact you can make your own teabags with t-sacs if you insist, tho it will generally taste better brewed loose.

Yunnan Sourcing's standard Long Jing is actually pretty decent and just $13/100g. That i wouldn't brew in a t sac, bec the leaf is bigger.

Good luck!

My go to:
https://www.amazon.com/dp/B010RV810W/ref=cm_sw_r_other_awd_9s34wbVNJQXHH

With the size 2 it's really easy to just curl the edge over the side of the mug while steeping too.

I use T-Sac brand when I travel. These are made in Germany. They're pretty good, but I never use them at home.

https://www.amazon.com/Modern-Filter-Disposable-Infuser-Filters/dp/B010RV810W/ref=pd_bxgy_79_img_2?_encoding=UTF8&psc=1&refRID=CQTY4VQKTX56WTD76MA2

You can actually do this if you buy "roll your own" bags. Something like this:

https://www.amazon.com/Filter-Bags-Disposable-Infuser-Filters/dp/B010RV810W/

But you will also need a grinder, or pre-ground beans, and in the end something like a portable french press or something like this:

https://www.amazon.com/Teas-Etc-Tea-Traveler-Ounces/dp/B003FGW71G

Might work better.