All these these tips are all well and good, well no they're not really. Through a wish to be helpful they perpetuate an odious practice.
Surely the question "should you?" should be asked before hasty insertion leads to regret.
I ask you to ask yourself is this gif really worth subjecting other members to?
Is it original or amusing?
Isn't it really rather crap?
Right click how big is it?
Is the size/amuse ratio OK?
Don't make a decision if sozzled or addled, you know that.
Any way you shouldn't be rushed into a decision, wait a day and see if you still want to.