Hi Darlene,
I offer both hourly and retainer packages to my clients. The primary reason I even started offering retainer packages was due to an unfortunate (and exceedingly frustrating)

incident regarding non-payment. Presently, I have clients on both hourly and retainer and I do like the guaranteed aspect of retainer, however, as Tess pointed out, there is more paperwork involved, i.e. tracking hours. Hope that helps!