How do you get a good start on a solve

I kind of just lose hope when I see a horrible cross case because I know the solve is going to be over 13 seconds...

I'm trying to me dual CN but its not working very well because I'm practicing and still can't get used to yellow

The start on a solve is very important because it dictates my momentum, if I don't start well, my f2l and last layer won't be good either.... on good starts I get 10-11 seconds usually with X cross but sometimes I just simply cant get an efficient solution which ruins by entire solve...