Bending branches
Can start with clothes pins attached above a emerging shoot.
To get a better crotch angle .
At finger size branches , spreaders are desirable.
1” x3” x ? Batton board with a “V” notch in each end works.
Have fashioned these out of branches from pruning, sawing a notch on the spot.
Having a bucket full of these of different lengths to choose from
1”x 1” x ? sticks with a finishing nail drove in each end , and ground to a point, also work , various lengths.
Painting them white will help keeping track of them if they fall out.

Yes , ! That’s my original art work .
Milk jugs ,etc full of water can be used.
If hung with a stiff wire “S” hook , they are easy to move , adjust. Also amount of water.
Also bags of soil + tape is good.
Strings tied to the ground ,/ rocks will work …
But are a nightmare for mowing . !
I think 65% is a good angle , don’t want it much flatter.