For full-length shots you can simply try and locate a nice patch of texture to shoot against – an old brick wall, hay bales or an interesting doorway will all work, for example. The idea here is that with little to no other elements in the shot, all of the focus will be directed towards the bride and groom instead.
If you’ve had time before the wedding day to scout out the location and you’re concerned about their visual qualities, then try branching out and taking a drive around the local vicinity in order to find some alternative shoot locations. Public fields or nice patches of woodland are fairly common around the UK; providing that they’re located within a short walk or drive of the venue, the couple may well be willing to make the journey in the name of capturing some great photos.
Visit the venue, scout the locations involved ahead of time for peace of mind. It pays dividends to get in contact with the venue and ask if you can come and visit ahead of the wedding to identify the best photo locations.
It doesn’t hurt to ask the staff their opinions on the best places to take photos too, as they’ll know the place like the back of their hand and can sometimes unearth a hidden gem or two.