We have several members who have made videos of their dogs getting an injection. You will see lots of different techniques for how to tent the skin (or not), injecting fast or slow... there are lots of ways to go about it and you can experiment to find the one that works best for your dog.
Tiggy:
http://www.youtube.com/watch?v=wLHD7lbbbXg
Chloe:
http://www.youtube.com/user/lovewesties#p/a/u/0/tauj4iQu14g
Xena in Brazil:
http://www.youtube.com/watch?v=t-Gr-IGYsz8
Lucy in the UK
http://www.youtube.com/watch?v=qiVGulYDCJU
Tiggy:
http://www.youtube.com/watch?v=wLHD7lbbbXg
Chloe:
http://www.youtube.com/user/lovewesties#p/a/u/0/tauj4iQu14g
Xena in Brazil:
http://www.youtube.com/watch?v=t-Gr-IGYsz8
Lucy in the UK
http://www.youtube.com/watch?v=qiVGulYDCJU