You know those things you can't get by without but you just don't like spending money on; like gas and tampons? I think eyeshadow primer is one of those things. For such a little bottle it can get pretty pricy, but your shadow won't last 'til lunch without it.
All you need for long-lasting shadow are two things you probably already have in your makeup bag: lotion/cream and a liquid foundation or concealer.
I used Equate eye cream and a little bit of my True Match concealer (I included the foundation in the picture as another option)
Of course, you will need some place to mix the products. I just took the lid off the cream and scooped a little bit of cream into it. Since I used concealer I used my brush as a mixer, but if you use foundation you can use your finger or a q-tip!
Mix the products to your liking, and voila! Your makeup will last plus your eyes will be nice and soft, and smooth!