I found using WD-40 works better cleaning spray paint tips than tipping the can upside down but is messy when you're trying to use the tube that comes with the can.
So I cut the top off an empty spray can and use it on top the WD-40 can
Step 1: Cut Off Top
Not all Spay tips are interchangeable and trying to hold a Spray tip on to the tube is messy.
So I start by using an old can opener (the type cuts the side of the can) to remove the bottom then use tin snips to remove the top of the can. File down the rough edges.
Step 2: Cut Tube
Using the tubing from the spray paint can, cut ¾ in off the plastic tube and use it as bridge to connect the cut top to the WD-40 can
Step 3: Try Out Tips
Attach cut top to WD-40 and try.