Flickr header (see below)

How to make one of these in Photoshop Elements:

Sizes ... dark blue background (Ctrl + letter N, & then blue colour splashed on with the Paint Bucket tool) : 2048 x 768 px ...

plus my sky photo re-sized & cropped to 2048 x 400 px. and then copied and pasted onto the centre of the dark blue one.

(Re-size the width to 2048px, and then crop the height gradually down to about 400px.).

Layers > flatten image ... or Ctrl plus letter E, before saving image (Ctrl + Shift + letter S, to get up the Save As menu).

More keyboard commands, which I use all the time ...

Ctrl + letter A ... to select the entire image

Ctrl + letter C ... to copy it

Ctrl + letter V ... to paste it onto centre of the background

Ctrl + letter D ... to de-select / undo your selection.

My thanks to Mary Irwin Watercolors ... Mary suggested these sizes, which have worked well for her.

Done