I've been using my Android phone, but want to know how you guys do it. I think I must be doing something wrong.
For myself, I use the app 'Comica' to make multi-panel images. Then I use 'Photo Resizer' on those to bring the image under the 1mb upload limit. Or just use the 'Photo Resizer" app to resize camera photos. Depends on what I want to do. You can also upload the pictures to an external forum image hosting site, like imgBB, and link them. The downside to that is if the forum image hosting site shuts down, aka Photobucket, you lose the images.
Take them with my phone or camera Transfer them to my computer Edit them as necessary (crop, resize, etc.) Upload them to my post
Make sure they are less than 1mb. I "airdrop" them to my laptop. Drag them from your computer to your post. If they're too large, you'll get an error message.