I had to give Oliver sub-q fluids for about six months and I found that warming the fluids helped ALOT. I had an extender set that gave me more IV line to work with and I just put the IV line in a warm water bath so it was warmed as it went through the line.

The other thing I did was to give Oliver some "treats" while running the fluids. The treats could be dry food (I don't feed dry food normally so it is a treat) or some canned wet food. This would keep him still long enough for the fluids to be administered. (BTW I also use an 18 gauge needle)