I agree with Heidi. Unless you happen to have some of the substitutions on hand, it would seem more worthwhile to just buy the correct product for the intended purpose. I don't have glycerin on hand.
Also, I worry about something like hand lotion being greasy, maybe if your inkpad is already dead, you could give it a try before throwing it away. I can imagine opening up the ink in a few months and having a weird science experiment! Same for coloring with M&Ms! In FL, that would just be an invitation for ants. I remember people using burnt sugar or milk on cards, same thing, to me that's just yuck!
I embossed a whole lot of Christmas cards over my stove burner before I got a heat gun. It works!
Ok, how about this one ... as a substitution for Washi tape, use scotch tape to pull up newsprint or magazine print, then glue to your project. I have some of this tape I made, can't say I've used much of it though! Also, you can stamp or ink over masking tape. If you do it on a non-stick surface, it might even be sticky enough to use without additional adhesive.
I don't color with markers much so my Bic MarkIts are an inexpensive option for me rather than investing in Copics. Sharpies probably work too.
Before I found Twinkling H2O's on clearance, I bought one jar of Winsor & Newton Water Colour Iridescent Medium. You can put a few drops in a water brush with water, shake well, and make any of your watercolors iridescent. You can also use it to make sprays.
Fun thread!