It occurred to me after a post I made the other day that a very simple technique to get the effect of a tilt (and shift, if desired) lens may not be widely known. I must admit I had never heard of it until I accidentally stumbled upon it a few years ago while cropping a panorama, but if your subject is stationary and you have a good panoramic stitching program you can use any lens in this capacity.
The technique is simply to shoot two or more rows of photographs covering the subject equally above and below the desired end centre point for a tilt lens effect (or left and right in the case of shift).
Even something as basic as a single story building can benefit and a wide-angle "falling over" effect can be avoided if one cannot get back far enough (or high enough) to keep verticals parallel. The following is a front on shot, full frame (as in uncropped, not as in 135 frame) taken on my X-T1 with the 10-24mm lens set at 24mm. I was stopped from getting further back or higher by my front fence, so to get the whole house in this was the least wide angle I could use.
Shooting one photograph with a lot more foreground in it (and so cropping the roof substantially) and one with more sky (so the building was "leaning back noticeably) I then stitched the two in PTGUI, in this case using the cylindrical projection, but this will vary on the number of shots taken in which case Mercator or spherical may work better. Then I cropped the extraneous foreground back to roughly 3:2 for a very standard-looking shot, but with straight verticals. The benefit of doing things this way rather than using a perspective tool in an image editor is that you don't lose image on the sides, nor does the software have to interpolate extra pixels or discard others at the same rate, therefore image detail is better maintained. Flick between the two in a viewer and the difference becomes very obvious indeed.
Using a longer lens and do several rows of shots will actually substantially improve resolution, but in that case not only will all the subject have to be still for a longer period, but you will have to use a proper 3-axis panorama head and have the nodal point of the lens accurately worked out and set as the rotation point.
If you don't take architectural shots enough to warrant the large cost of a true tilt/shift lens, then this is a handy technique to bear in mind.