Before you finally choose your knitted pattern, take some time to knit a work example – however it's not the work example you usually knit to measure the number of stitches in the breadth and the rows in the height.
Only by that you can form a better opinion about the possibilities and the effect of the pattern according to your way of knitting – especially if you deal with a fancy pattern.
This work example should help you to make a deliberated decision and become known with the method of operation of your pattern before you start with the real knitting work.