What I do is after I'm done drawing up as much of the solution from my spoon as I can, I add just a few drops of water onto my spoon. Then I take my syringe cap (or end of my plunger) and stir up the water I placed there over the surface of my spoon and cotton. Then I'm ready to again, draw up all that is left in the spoon - adding that rinse to what I originally drew up into my rig. It's the same idea as doing a rinse shot, except this way you're not leaving the spoon and cotton exposed to the elements for any longer than I should, reducing risks of getting extra bacteria into a second shot.
This way your first shot has almost 100% of what you originally put in your spoon.