For google photo (this is how I do it, anyway):
photos.google.com to load up your photos/albums
Click on the image you want to share
When it is fullscreen, in the top right is the share icon (leftmost icon)
click "Get Link" (bottom icons, top row, right side)
Click link and open in another tab
Click image in new tab to make it fullscreen (though this is likely optional)
Right click on image and select "Copy Image Address"
Insert that image address into the RC [ IMG ] system or use their picture insertion link that does it for you.
You can resize the image through modifying the end of the link where it says "w1246-h934-no" the wXXX is the width in pixels, and the hXXX is the height in pixels. You can change it to whatever you want, just keep the aspect ratio the same (use windows/mac calculator if you want to know what multiple to adjust it by; the image below is downscaled to 667x500. In my tank thread I mentioned the normal scale I adjust it by, I think it's somewhere around 900x700 or something? If you right click the pictures in my thread and look at the URL you'll see the sizes there.).
I know it's a pain, but it's easier for me because my life revolves around google at this point. Between google and the economist, I'm set
