ways to correct keystoning/ perspective in photoshop elements

I've been using the scanner for little pictures but larger pictures just don't work. I cannot take a square picture so I always have to correct it.
Here are some links for that:

• https://digital-photography-school.com/how-to-fix-keystone-issues-in-photoshop-elements/
• https://digital-photography-school.com/correcting-perspective-in-photoshop-and-photoshop-elements/
• http://www.essential-photoshop-elements.com/straighten-leaning-buildings.html
• http://www.photoshopessentials.com/photo-editing/keystoning/

A lot more messing around than in my old photoshop program but still doable.

Secret Knowledge by David Hockney

Secret Knowledge
rediscovering the lost techniques of the old masters
by David Hockney
isbn: 0-670-03026-0

Very interesting book. Lots of examples. He presents his case that many of the old masters probably used optical devices such as the camera lucida to make their paintings. He shows subtle clues from the paintings that indicate that optical devices were used. He also recreates experiments showing the effect of optical devices on sketches and paintings.

4x6 pen sketches, hart park

F hand pencil sketches 5.5 x 8.5

I have been listening to old Savy Painter Podcasts and they talk about the importance of practicing/ sketching often. So decided to continue on with the sign language alphabet. I was scribbling in a hurry to get the last one done. I noticed that it got with the side of my hand because I worked all over the piece instead of working left to right. Need to remember not to drag my hand on the paper. Just using mechanical pencil.

Center Lake near Silver Lake, 6x8 acrylic 4/26/17

Used my 4 favorite colors: Paynes Gray, Hansa Yellow Opaque, Burnt Sienna, White.

Painted at a friend's house. Very beautiful there.
A lot of painting buddies showed up.

whitnal park 6x8 acrylic 4/21/18

Sunny but chilly.
Paynes gray plus Hansa Yellow Opaque makes the right shade green for springtime trees and grass.

acrylic figure sketches; 6x8, 8x8; 4/18/17

Model didn't show up at sketch club so we did approximately 15' or so sketches of each other.