Like Zane_C said, you're probably solving just fine, but need to look-ahead better to have more tps. I don't mind doing one though, so here it is:
Scramble (You didn't provide one so I just used generated one): B' U2 L B' F' D2 L B R2 U B U2 B U B2 F D' U' R' U2 B' R U B' L' (green on front, white on top)
Cross (Orange on front, yellow on top in this case): D' L B F2 R' D'
Pair1 (I see the pre-made red/green pair): U L U' L'
Pair2 (Saw green/orange while solving the previous pair): U' R U R' U' y L U' L'
Pair3 (Saw blue/orange): U' R L' U L (easy spot on blue/red so keep solving without putting R face back)
Pair4: U' R' U' R U R' U' y' R' U' R
OLL
PLL
Nothing fancy, just normal solving. There's probably algorithms I could have used for something but I don't really know any f2l algorithms. For what it's worth, I solve pretty much how I used to solve when I was struggling with sub20. The only difference is that I do it faster now since my look-ahead is much better. You can learn some nice tricks for f2l or whatever you want, but in the end, that won't make the difference from sub20 to sub15.
Good luck.