Here’s an example trying to match your situation. Starting with the basic shape first:

This is where I like to select all edges I want hard and use the bevel operator to establish quick holding edges that I can clean up later:



This gets us most of the way with only the corners needing cleanup. Note the blue arrow pointing to a “utility edge”. This is not meant to be hardened but I overshot the triangular corner so the bevel operation is clean as it exits the corner. I can simply collapse this next:

Add the secondary (magenta) edge loops so the cleanup doesn’t stretch awkwardly far. Collapse the upper triangular corner and spread out the lower triangular corner.

Hope that makes sense. I made a note to possibly demo this example during next week’s stream.