Being helpful, curious, and empathetic can't be faked. Hire accordingly.
A policy banning cellphones? No food or drinks in the library? The resulting often mean and ugly signs? Insanity, all of it. The library is a growing organism, right? Let's grow.
Start by keeping a list of every time you say "no" to a patron. Review that list weekly. Some policies are enforced for no better reason than "we've always done it that way."
If you must ban something and must have a sign attempting to enforce the ban, make sure it isn't disrespectful and that it looks nice.
Practice. It makes perfect. Anything gets better with revisions, so it is pretty unlikely that your library can optimize a service on the first try. Do you know what Apple computers did before launching its first retail store? They built one in a warehouse to see if it worked. After observing people use the store they were able to iron out the problems before exposing the public to them.
You can do similar experiments in your library, even without a spare warehouse laying around. Bring in people before or after hours and watch them interact with a new collection or furniture arrangement. Learn from them, make it better, and try it again. Test a new webpage design (even just on paper) with some Library Friends. Improve the page and test again to see if it is easier for people. Devote one reference shift per librarian per week to never sitting behind a desk and report back after a month.
Libraries have limited resources and can't do everything they'd like to do. A limitation? Perhaps, but also an opportunity. These limitations should focus libraries on what's most important and allow them to cut away unimportant services and features.
Taking away services? Won't people be angry? Maybe, but with adequate research a library should be able to figure out its least popular service and start there.
By doing this a library can free up as much time, effort and money as possible for what really matters to its patrons. Only then can it do as good of a job as it should be doing.
It is far better to make 50% of your patrons ecstatic than it is to make 100% of your patrons barely satisfied.
The same thing applies to your library's website. Cut it in half and devote all of your efforts to making the remaining stuff shine.
A library can't be successful unless it is in the habit of learning about its community. User research: do it! There's just no other way for a library to know how it can best meet the needs of members. Instead of spending more time on a collection development plan, concentrate on a user research plan.