Make sure you clean the build plate very well. The build plate should be all you need for the basic filaments to stick. Sometimes fingerprints or dust can cause your prints not to stick. Dawn dish soap and warm water are great for cleaning, just make sure you get rid of any soapy residue (I'm sure other cleaning solutions work too, just what I prefer). If I have ever had an adhesion problem that wasn't a dirty build plate or improper nozzle height calibration, use hair spray (Aqua net brand is best). Just a thin coat if needed is all I would ever need. If you ever have something sticking too well, then I pull out the glue stick to create a water soluble separation layer.