[tapwelder]

I use straight cuts almost exclusively. It just keeps me from changing the saw position and faster on the cutting end.

As for capping I use metal squares smaller the the OD of the tubing. I also leave the open end of the tubing recess so when I add the cap it sit flush. Choose the cap smaller so you can grind and shape the weld without grinding the weld away.

For a decorative look you can actually leave it raised and shape the metal cap.