Select and Mask/Filters

Choose the lasso tool, marque tool, (any tool used to select something), and then on the top will appear the option to select and mask. Click it.

Here you can select your subject or object in detail. Each tool in the toolbar helps select part of what you want to cut out as a brush tool. The top one is Quick Selection tool: calculates, as you "erase" the overlay, what area you want to select. As you remove and add overlay, the better it gets to guess your selection. The Refined Brush tool: used to select refined areas like hair. The smaller the brush the more exact it is, but it could still mess up depending on the resolution of your image. The Brush tool: used as a brush without any advanced AI behind it. What you brush over is what you select. The Object Selection Tool: used to select an object much quicker. Then Finally you have the Polygonal Lasso tool: much like the one already on the default toolbar.

To the right I am only talking about the top. In View Mode, next to View is an arrow that drops down and has a different arrangement of overlays to see your selection better. The slider below it helps drop the opacity to continually see the image clearer or your selection clearer.

Once you press ok, a selection line appears around what you selected. Use the keyboard command Command+ Shift+I to invert your selection to erase everything around it rather than inside the selection.

Once you erase, you can deselect your selection, and view your image. (In case that the refined brush makes it look scratchy, you can press Command+Z to go back to your selection before you inverted it, then Select and Mask it again. It will save your selection so you don't have to do it over again).

To apply a filter, you first merge all your layers. Shift click your layers (or sometimes the bottom layer to select all) and then right click/use two fingers to select merge layers.

Finally all you have to do is select a filter from filters and your good to go. Filters help tie all your images/composites together instead of making it look like a collage.