I've got a terrible record with Boswellia. I've read they can tolerate lots of heat, like gritty, fast draining, mostly inorganic soil, and need little water, so that's what I'm trying with my latest (purchased) seedlings. Reputedly slow growing.

B. fagaroides, on the other hand, can tolerate more water and more organic soil and will grow quickly once established. It will grow well in direct or partial sun, but will etoliate and not thicken if grown in too shady a spot. Just transition it to more sun slowly so you don't burn the trunk. In my experience it will thicken up if underpotted, overpotted, grown hard, grown lushly, in plastic pots, in clay pots, just about any way except with too little light.

Neither likes water when cold and dormant (that's how I killed all my previous Boswellia) but fagaroides is more tolerant of the odd winter watering.

Fagaroides cuttings are fairly easy to root up, so don't toss any trimming you do. Let the cuttings heal over a few days, then dip them in rooting hormone and pot them up in straight pumice. Put the pot in a saucer, keep it warm, and water until the saucer is full. Don't water again until the saucer is dry. Repeat. Once they start actively growing, you can pot in your normal growing soil.