BOSS GT-10

After one month meeting with my new Rock Group I realise that my guitar processor Boss GT-10 does not sound the same. So I decided to leave the user manual in the bathroom in order to read a bit twice a day (after some week ends even more times a day). I had to choose which preamp to use and its parameters, pickup type and which patchs suit for every song. I have found that it is a very hard job to do. Could any one of you, friends, give me some advices?