I use a Tarantula Broadhead Hip Quiver that has a belt and also can be strapped to your leg about 3 inches above your knee. The model that I use can carry up to eight arrows and it can be worn on your left or right side with the arrows angled slightly rearward. You can comfortable kneel, or climb a tree with these quivers. Tarantula also makes a 4 arrow version that I believe Len Backus may carry in his Gearshop store.
If you are not looking to carry your arrows where you can easily access them, then I would suggest an arrow tube that fits neatly into the zippered arrow compartment in the TAC15
soft case. These arrow tubes can easily hold a dozen or more arrows and offer excellent protection for your arrow vanes. They also have a nice carry strap that allows one to easily throw the tube over your shoulder and go for a walk, when needed. I use these for my target arrows when shooting long distances. They are around $20. each and I think Easton Archery makes a version. I use ones that are made in the UK because the are a bit thicker in their construction of the plastic that forms the tube. All are adjustable for length, so size is not relevant to what arrows you're using.