Anticipation is key - somewhere safe to get lines and fenders ready, even if the means grabbing an empty alongside pontoon somewhere you can easily get on and off again. As in going up the Hamble ...
And not all marina berths are safe at all states of the tide - slack water is best for some of them. Again, phone ahead.
I've always found marina staff very helpful if you tell them you're single handed; they've often allocated me a favourable berth, and come down to meet me and take my lines, or even stood at the berth to greet me so I know where to aim.