I bought some empty squeeze bottles for making custom home sauces.  An easy starter was Sriracha ketchup.  I began with small quantities and used a scale to set my ratios.

4:1(ketchup to Sriracha) was a pretty good blend.  You could taste the chilli sauce with every bite, but wasn’t left in flames after eating a few tablespoons of the stuff.  Hot heads might want to try a 3:1 or a 2:1 ratio.  Only filling the squeeze bottle up a little means you can tweak your mix ratio after sampling.

A pile of Wendy’s fries provided an excellent test medium for my new sauce.