The snap-T is generally designed to be a square angle-change cast but it can be made at a more acute or obtuse angle depending on (1) the plane of the d-loop before the cast (2) how the pull/push is directed and (3) where the anchor lies.
Skipping the details for a minute, as long as you can lay-down this formation in a manner that it can be swept up into a d-loop, the most important thing is that the d-loop is aligned with the forward stroke - follow the 180 degree rule.
However the shape of the line on the water determines the sweeping path, and the sweeping path influences the d-loop - thus pay attention here too.
The shape of the line after the snap is a sort of 'candy cane' or "U" with 54-65 ft lines one leg ends at the rod tip and the longer leg lays on the water with only the anchor and fly upstream of you on the final casting side of the body.
Make all moves with the body, not just the arms...
a) lead the initial lift and pull toward the middle of the river a little more for closed angles
b) when pushing the rod tip underneath, cross to the inside toward the shore a bit more
c) use a shorter belly line for more maneuverability
d) pay special attention to degree of rotation at the end of the sweep - watch the d-loop!
e) wait for the sweep momentum to form the d-loop... after the stop it may take a full second for that d-loop to swell out and back
f) look for the end of the flyline to pivot before making the forward cast, this means the d-loop has formed fully
Lastly make sure the anchor and fly are on the correct side of the cast or risk a hookup of the wrong species
Upriver wind, left bank? My pet cast - the upriver snake is my favorite, but I will use a single spey most often for simplicity and power.
Good luck casting!