Not sure if this has ever been posted before but I thought it would be a nice tip.

We recently started doing a lot of complex welded frame structures and I love the weldment tools available.
So I started making 3D sketches of the frame structure and that was pretty neat. However, I find that the 3d sketching tends to be cumbersome, much harder to add relations to, and seems to be quite quirky and easily becomes overdefined. So, what I thought would be even easier, would be to start my frame as a simple modeled solid. Switch my view to wireframe mode, and filter edges mode. Start a new 3d sketch and 'window select' all the edges and hit convert entities. Delete the solid bodies and it's done..... a complete 3d sketch and easily parametric. All the while not having to deal with complex 3d sketches. What's great is that you can use this sketch geometry to create weldments.

Here is a simple example and screen pics.

Don
CSWP