In general, should all woods, including hardwoods, be pre-conditioned before staining?

I’m making a small hall bench using maple and cherry wood, and I have a question about finishing. I intend to colour the whole thing with a cherry stain. Is it necessary to pre-condition the wood first?

No, I wouldn’t pre-condition your project. I’ve seen great value in applying pre-conditioning liquids to softwood with high resin contents because it evens out stain absorption and colour. Without pre-conditioning on most pine, for instance, you get blotchy results. But since hardwoods don’t contain resins, that won’t be a problem for you with this project. If in doubt, prepare some samples on scrap wood and see what the difference is. I suspect the pre-conditioned surfaces will be lighter, though the colour will be just as even compared with the non-conditioned sample. If you’ve never stained cherry before, there’s an advantage to the process that you might not realize. Although cherry turns a rich brown colour with exposure to light, there are sometimes areas of light-coloured sap wood that will never darken. Applying stain to cherry projects evens out these light areas, boosting the consistency and richness of the surface.