When receiving invites to in-house deign conferences I often wonder if those that sponsor these events have been to an in-house group. I find it more than a little misleading to tell folks they will learn how to be better in-house designers by listening to the creative director of Fossil watches give a talk about how their group is organized. Let's face it, if you're not doing great work at a fashion brand, something has gone terribly awry.
Most folks that are at in-house groups really want to figure out how to behave more like an outside firm or agency. They want to get out of the game of creating forms, and occasionally getting to branch out in intra company communications. They want to figure out how to get their leadership to trust them with the public face of the company, rather than using the "cover-their-ass" technique of going with outside consultants. Basically they want to get out of the bowels of the building and onto the upper floors.
Unfortunately I don't have any real prescriptive answers to those questions. In-house groups that have upper level buy-in, operate like an agency within he company, and do knockout work generally have grown organically. I would suggest that there are general behaviors that can help lead those groups where they want to go, no mater how stodgy the organization seems.
First, know your business. The design part certainly, and the business of those you work for. if you don't know it, you can't communicate it and you certainly offer no value to the company other than laying out forms.
Second, make every project you do as spectacular as it can be. Even if it's a half inch classified ad, make it the best damned half inch classified ad anyone has seen. When the quality of work is high, eventually people will notice (particularly if the service level that goes with the finished product is high)
Third, act like an agency. Offer suggestion where and when you can. If you suggest that you care about what your company does, those at the top will eventually notice.
Eventually Can Be Eternity
Keep in mind that eventually may be beyond your stay at the company. Leadership differs. Appreciation for the work you do only gets shown when the company's interests rely on your work. That may happen tomorrow or ten years from now. The key is to seize every tiny opportunity until the big one comes. Ask for work and eventually you can get it.
It's an unfortunate truth of in-house design that it's under-utilized. However, designers can't assume that lack of utilization means lack of appreciation. Appreciation only comes when the higher-ups have you on their radar. The only thing you can do is great work so that you can be more than just a blip on their screen.