A couple of others things you can do that Digger hasn't mentioned.
You can detune your pinpoint a couple of ways. The easiest way is to lift the coil an inch or so; or you can hit the pinpoint button twice more after you are already in pinpoint mode. Go over the target again and you will find that you will now have a very small target area, which makes it real easy to find the target. If you lose the signal, just lower the detector a little bit and you will reacquire the target again.
Although the depth meter isn't the best, if you look at it for the shallowest reading, then this is also will tell you that you have got the target in the centre of the coil.
As another method; you can go into pinpoint as normal, go over the target and pull it towards yourself (wiggling a bit as you go). When the audio stops, the target has just passed under the 12 o'clock position of the inner coil.
Apart from the 2 sizing methods digger mentioned, if you simply listen to the strength of the audio of the pinpoint, the on shallow targets, you can work out what some of them are.
Have fun with the 705.
Mick Evans.