I think it is normal for spin coater to throw some precursor. I too have experience that when I was working on that a long time ago, now I don't. This is what I used to do. Limit to few drops through a pipette, annealed it in between each coating to dry the film in a hot plate, repeat until desired thickness. If the film is not sticking at all, check the viscosity to your precursor solution. Is it a sol gel route?  Make sure you cover the side walls of the spin coater with some tissues.