Determining reflection points

FIRST REFLECTION POINTS :

Speaker angle is irrelevant.
Tweeter > Side Wall(s) > Listening Position ( ear level ),
Tweeter > Ceiling > Listening position,
Tweeter > Floor > Listening Position.
The easiest way to find 1st reflection points is to use a mirror. Seat in your listening position while another person slides a mirror ( small, about 4"x4" ) along the side wall until you can clearly see speaker's tweeter. NOW you have your 1st reflection point. Same procedure for remaining wall and ceiling ( I am assuming you already have rug or carpet on you floor )

Mrjstark is correct for most speakers, and correct about the mirror technique.

Note that line-source speakers don't have a significant floor and ceiling first reflection. Note that bipoles and dipoles will have a significant first reflection off of the wall behind the speaker. And if the speakers have a well-controlled radiation pattern, it's possible that enough toe-in could essentially avoid the first near-side-wall reflection.

Duke

Thank you Mrjstark. That makes it easier.
And thank you Duke. That may make it even easier. As always Duke, you rock!