garrett gta 500

Hi guys/gals i just recieved my new detector and im going to a roman settlement sunday being new are there any tips or ideas to improve my chances of finding something ive had a go of it in the house and i can cut everything out but still pick up my wifes ring so discrimination on it is great but and heres the big but what sort of setting for roman stuff or no setting at all these are headaches which i enjoy as its all part of the learning process if i find anything i will post pics thanx