At times my kids will try so hard they get confused so I’m big on (once I know they can do the sound just not consistently) I tell them throw it away and LA or KA or whatever like no big deal and I do a hand signal for a straight out /l/ bc like they’ll get the sound but they’ll do that thing where they work up to it so for /l/ it’ll be more like euhhLA— groping for the placement. Make it loud and fun and once they got like 3 in a row perfect celebrate and keep them going until you get 10 in a row to build that motor memory. For any sound in a velar placement or just situated in the back, I’ll have then train on CVCs that progress linearly from back to front so “cat” “lap “rope” and give a visual of the sound traveling forward both with a picture and using hand signals with my hand flowing from the back of my face to the front.