Perforated window film is the usual answer, it reads as solid graphics from the street while people inside still see out and get daylight. Full opaque vinyl is for areas you actively want to hide, like a stockroom wall. Coverage of thirty to fifty percent of the glass usually does the job without making it dark. We had ours done through promoboxllc.com/, storefront graphics started around $350 for our size. Keep the message short, people are walking or driving past, so a name and one line beats a paragraph nobody reads. Measure your glass before requesting a quote, square footage drives the price more than the design does.