I use the hole punch tool. Then put some boiling hot water in a Yeti... Dip in the end of the tubing in the hot water for 5-ish seconds, the connectors slide right on... Easy peasy!There's a tool for that.
OR you can use a very small Phillips head screwdriver, pinch the 1/2 inch tubing so it's firm, and gently poke a guide hole for the 1/4 inch barb.