So your not finding a great deal of items on your permissions.
Here i am going to list a few sound pieces of advice which will hopefully improve your finds rate, no matter what machine you use.
i will start off with something so simple, but so important, your swing.
If you are going to swing your machine in a pendulum fashion, you will lose a high percentage of the ground you cover. The way you should think about your swing is this; Imagine your search head is a steam iron and you are ironing the grass/soil in front of you. If you have a pendulum motion you will only iron the fabric in the centre of your swing, the rest will remain creased. We don't want any creases, so let’s keep it level.
So you are now covering the ground in front of you correctly.
Once you are swinging in a fashion that covers all of the ground in front of you, then you need to now slow down.
I see all too many detectorists going hell for leather up the field swinging like a good thing but only covering about 10% of the ground they pass over. I recently attended a rally where on the second day of the dig (over 60 detectorists) a quarter noble was found within 15 meters of the car park. The area the lucky fellow found it had obviously not been searched properly as everyone had raced off over the top of it. Were back to the ironing again. Make sure as you move forward you cover every inch of ground within your swing range, don't leave any creases.
In my experience, one tends to find a high percentage of things within the first hour of detecting, because we tend to dig more of the "iffy" signals. I recently swept over a spot with my F75 and had an iffy ring pull signal. i had dug at least 15 ring pulls up already. For some reason i did indeed dig the signal, and at about 14 inches i happened upon an intact croatal bell. I reckon that after another hour of detecting i would not have bothered digging that signal. So I guess what I am saying is dig as much as you can, for every 15 disappointments, you may well get one surprise. At some point you will become one with your machine, and begin to know the iron signals. It is for sure though that the old adage of "you will only learn by mistakes" is very true.
And finally, get a probe!
No, don't rush off to the doctors; it's not one of those types of probe.
I will give a plug now to what i and many consider being the best probe on the market. The Garratt Pro Pointer is gods send if you can afford one. I don't know how many times i have missed a tiny object by a few millimetres when i have dug my hole. This can be frustrating as you start to doubt the ability of your machine. With the pro pointer in hand, you simply probe around the sides of the hole and, bingo your find is located. You can then recover the item without damaging it with a shovel strike. The probe also comes into its own when you happen upon a deep target. Occasional you will get a signal from a deep target. You dig your hole and wham, the target as gone. The void between your search coil and the target causes it to disappear! Simply probe the bottom of your hole, and hey presto the item shows up. I wonder how many deep treasure finds have been left in the ground after the signal disappeared?
Now let’s get out there and cover the ground properly.
Good luck and god bless.