Resizing and compressing are both required. A lot of folks resize a picture until it is so small that when clicked on, it only enlarges a little bit, and is therefore hopeless. Resizing below 500 pixels
wide is bad...don't do that! Resizing to around 650 to 1,000 pixels wide is good.
First thing I do is give the image a title, so I know what it is. "Model.jpg" is of no help, so put some details into the title. Something like: "ImpAct Howard Rush Poland Plane.jpg" would be good! If you need to rotate the image, that should come second. If you can reduce the size by
cropping, do that third. Then, fourth, resize to that 500-1,000 pixels width. Lastly, you need to
compress the file and save it as a jpeg. Jpeg or ".jpg" is the most efficient file type that I know of...much better than .png, from my experience.
All this is easily done using IrfanView software. IrfanView is a "freeware", meaning that you can download it for FREE. You still need to figure out how to work it. It will do a lot of stuff that we're not interested in, but I have done one picture in 15 seconds to around 100kb, which is always my target. If it comes in at 150kb, I might just go with that. If you think this is too difficult, SSW only allows a 50kb max, and that can be a challenge if the picture is not taken with any thought toward file size (grass foreground sux!).
If you download IrfanView, be sure to get the correct one for your computer type (PC or Apple). The place to get it safely is "TuCows"....maybe spelled wrong. I don't know anything about tablets and such, so you're on your own there. If you are having problems figuring it out (on a PC), I'll help, but just a few clicks and reading the dropdown menus should get you going.
Remember to use a logical sequence: Name, crop, resize, compress...and "save as" after each step. From the "crop" sequence onward, I add a "%" to the end of the name (before the .jpg) so I can figure out which version is which. If the latest version is crap, delete it and go back to the last version. I like to put all pictures "in process" into a "Test Pictures" folder on my desktop, so I can quickly find them. When you finish reworking a picture, move it to your "CL Pics" folder or whatever. If you want to save the original, you can save them in a folder just for them, but I seldom do that.
Steve