I think a little welcome card sounds nice, not too pushy but helpful. You may want to put a note on it regarding what day the rubbish is collected. I always used to welcome new neighbours with a card like this. New neighbours often have loads of rubbish to get rid once they have unpacked and knowing when to put it out prevents them falling out with the rest of our neighbourhood due to them putting bags out on the wrong day. I also always say if they have any problems or questions about the area to feel free to ring our doorbell at any time. Luckily, we have lots of lovely neighbours here.
When I was living in Germany, it was an old tradition to welcome any new neighbour with a round loaf of fresh farm bread with a little glass container filled with salt in the middle and a bottle or water or wine. The local bakers always used to provide this, beautifully presented with braids on the tope of the loaf. It was to give the neighbours refreshment, nourishment and spice for their new home. This is still practiced in villages and small towns all over Germany and most often also comes with an invitation for coffee / cake with the family and other neighbours. I know this wouldn't go down well everywhere here, but it is a lovely sentiment!