URL is the most important criteria for Google Images. Dont underestimate the name of your picture while uploading it since its name appears in URL .

http://img.googlepageleas.com/template.jpeg FALSE
http://img.googlepageleas.com/blogspot-free-template.jpeg TRUE

 Alt Your Image
ALT tag is the second most important determiner for Google , typing keywords to ALT tag will affect your results positively.But do not exaggerate it and type only 4 or 5 keywords.

< img src=”/template.gif” alt=”free template” > FALSE
< img src=”/template.gif” alt=”template pictures , free template blogspot , template blogspo free “ > TRUE

Title Your Image
TITLE tag is the third most important for Google , i advise you to use ALT tag instead of Title tag .

< img src=”/template.gif” alt=”free template” > FALSE
< img src=”/template.gif” alt=”template pictures , free template blogspot , template blogspo free “ > TRUE