Goals....how high is too high?

I usually set myself goals but do I make them too high? I guess if I had been writing properly over the last few years the goals I had set myself wouldn't be that high but maybe I need to scale back and be a little more realistic this year...and build my way up and if I surpass those goals even better. I want to make this year a success and the only way to do that is not stress myself by setting unattainable goals....change that to attainable ones and the year can only be a success....of course I will have "DREAM" goals as well....and by making the achievable ones the DREAM ones might become a REALITY