How to snip same part of screen as last time?
Solution 1:
Greenshot has an option to Capture last region
. Highly recommended.
Also very easy to do quick edits such as highlighting and obfuscation:
Solution 2:
As far as I know there is no way to "re-snip the previously snipped area" using the snipping tool.
The best way to achieve a similar functionality with the snipping tool is to the Window Snip or Full-Screen Snip available in the Mode Menu. Clicking the same window showing a different section of code etc. and trimming it down to the section you want.
Alternatively the open source tool ShareX looks to have a similar functionality as you describe. The menu options for that are further described here in a GitHub feature request for said functionality.
ProTip 1: The keys Shift+Win+S launches the new/alternative (?) snipping tool in Windows 10 quicker.
ProTip 2: Windows 10 in 1903 now has a multi-clipboard build in, turn it on in the settings, and you can use Win+V to paste any of the last 10 (?) copied items.
Solution 3:
One fairly straightforward way to do this is to separate the capture operation from the crop operation. Capture either the entire screen with Ctrl+PrnScr or a window with Alt+PrnScr; paste into an image editor which supports layers1; repeat until you have all of the captures as layers of a single image; then crop the image and save the layers out one by one.
1 I use the GIMP, but I'm sure there are plenty of other options.