'It has long been an axiom of mine that the little things are infinitely the most important.' -Sherlock Holmes, A Case of Identity
Design is an art, true, but design and art are not the same. In art, liberties can be taken, but in design, attention to detail is a must. And it could be said that too much research may never be enough. No matter the size of the client or job, a bit of sleuthing can make the difference between success and failure.
In the late 90's, an ad campaign was launched by Quilted Northern tissue featuring cartoon women quilting. Though the intention was fine, the ladies were 'quilting' using knitting needles. This was a costly mistake, teasing the sensibilities of a large demographic: homemakers and housewives. The campaign was eventually revamped to show quilting instead of knitting, but the lesson wasn't a nice one to learn. This is where research could have saved them a lot of time and embarrassment. Knitting and quilting may both use needles, but that in no way means the two are interchangeable.
Agencies and designers work with a lot of different clients. Though it may be familiar for you to work for a coffee shop if you love coffee and know a lot about it, it may not be a simple when the client deals in something outside your realm of expertise. Don't be afraid to take to the books, so to speak, and learn some things. Start by listening to your client, ask lots of questions. Dig deep and pay attention to the smallest of facts. This will not only make your design better, but can really help establish a trusting relationship.
Next, research every angle. If your client has something to do with music and you aren't a musician, give yourself a lesson in musical theory. Don't go by what you think may be okay, start out with a strong foundation and build your house there. You can have a design that's technically good, but if the base concept isn't sound, that design may end up on the scrap heap. And pay special attention to symbols and what they mean. A symbol or term may have a completely different meaning to one group than it does another.
Designers can be crunched for time more than we'd like, but our clients aren't always of a 'get it to me when you can' mentality themselves. If you've listened to your client, gotten to know them and their business, and done your research, what you deliver will be the cream of the crop. "Measure twice, cut once" as they say also applies to design. When you bring your client something that's thoroughly researched, it's easier to move forward without time-wasting error correction.
Jacks of All Trades, designers are detectives with sketchbooks. Knowing a little something about a lot of subjects isn't only beneficial for a trivia buff or Jeopardy contestant. These days, when information is so readily available, there's no excuse for errors of continuity. Be respectful of your client and good things will happen. And remember, you can't quilt with knitting needles.