flaming fingers

Hi; I just installed Express Scribe and it's working very well for me. I am a medical transcriptionist and have just started a new job that requires ES. I'm having trouble figuring out what %'s to use. There are so many variables. Can someone suggest what those should be set at for variable speed slow and fast as well as rewind and fast forward mode, ('m using constant speed) rewind step and forward step % and speed %. Right now ES is making it difficult for me to stop and then relisten to the dictation. Thanks.