What you need to do is what is called a "wash coat." It is commonly done in commercial finishing so that woods that tend to blotch, don't.
What you will find that in addition to getting the sealer thinned correctly is that you spray technique will need to be very good at laying on a very even coat. The amount of material applied will vary with what you are attempting to accomplish. In general if you apply so much that it looks shinny while wet, it is way too much. Next a very light sanding with an abrasive sponge, Clean. Apply stain, use a wiping technique that produces the most even result possible. Next could be either the first finish coat or the toning coat. Toner can be made by just putting a bit of stain in the top coat and using it to get the look you want. That can be darkening the entire surface, correcting unevenness in color or purposely shading. Most of the time several passes with the toner are done so that no hard edges show. It takes considerable practice and a good gun. After the toner put the final top coat on. You may want to vary the amount of top coat, due to the variable amount of coats below the last top, so the sheen is evened out. Finishing really is an art. If you are finishing a porous wood you may want to do a grain fill with a tinted filler. On really porous wood it often takes two filling cycles.
Particle board can look pretty good finished. So can wafer board, OSB. Just don't expect them to look like walnut. And don't use the board, (trash) they sell at the big box stores.