Smoke during my aluminum sign cut showed me feed rate flaws

I was making a custom sign from aluminum plate on my shop CNC router. I programmed the tool paths but guessed on the feed and speed. Part way into the cut, I saw smoke rising from the material. The feed was too slow, so the tool just rubbed and heated up. I hit stop right away and let everything cool down. After that, I recalculated the chip load and ran it again with no issues. It was a simple mistake that cost me time and a bit of material. How do you guys figure out your starting feeds for new jobs?