Perhaps 2 points:
Try to fly more often than once a week (if not doing so already). If flying just once a week, a lot of currency is being constantly lost. If you have just 1 day a week free, try doing 1 flight in the morning and 1 in the afternoon.
On landings, as BPF says, a firm landing is fine and is indeed more or less necessary if landing on a short-ish runway or in any sort of crosswind. IMHO the most important thing is to fly a good approach trajectory, so work hard on maintaining the "picture in the window" despite turbulence, wind shear, and watch the airspeed at the same time, all the way down.