I belatedly got round to putting my photos of painted Dalek and not-Doctor-and-Amy miniatures on deviantArt, and got favourited by an admirer of miniatures in general.
And of course that got me thinking, that would be a way to come up with odd crossovers if you have a collection of unusual miniatures. Pick one and make it a major visual for an episode.
Not that I use miniatures, but every now and then bringing out a figure and going “you see this!” can be very effective.
And just looking at that list of favourites, I can easily see the Doctor meeting these guys or this chap or this fella...