At a very high level the principles of good project management (focus on the end product, have a viable business case, learn from experience, tailor your methods to your needs, manage the project in stages, clearly define roles & responsibilities, open & timely communications, etc) are universal across project types. You should work to ensure these principles are followed on all projects.
In terms of specific methodologies, look at your needs, your client's needs, your corporate culture and the team you have to adjust your approach and overcome obstacles. Get a consensus from all the key stakeholders about how much control over the project they want and the level of documentation they require.
The key point is that your method needs to be tailored to what you require. I'm sure most PMs have worked in environments where you fill out X, Y and Z forms/documents because "that is what we do" without any real organizational realization that all projects are unique and that there are cases when you will have to do "more" and cases where it makes sense to do "less". For example, you likely don't need project plans with identical contents for each of two projects when one is 3 months long and worth $50,000 the other is 18 months long and worth $1 million.