Some Basic Approaches
1. Define the Problem - The first thing in problem solving and decision making is to define the problem or issue that you have encountered. Most often, new managers will react to what they think the problem is, instead of identifying what the actual problem is. By defining the problem, you get a clear picture of what is going on and therefore, can narrow the focus and solve that one problem. Communication with others who are experiencing the problem is helpful as well; it's important that you don't "place blame" on anyone, as the problem may not be human error but maybe technical or even an element of weather.
2. Look at Potential Causes - Jumping off from the first point, find out what could be causing the issue. Again, it's important not to put the blame on one or more people, but to get their insights into what the possible cause could be. For instance, if a presentation paper is missing or lost, don't automatically assume that it didn't get done or that the person lost it. Perhaps there was a technical failure (hard drive crash, power outage, etc.) or the file was saved elsewhere.
3. Find Alternatives on Solving the Problem - Essentially, begin listing several ways on how to solve the issue. To go with the example above, see if there are backup copies for the presentation. If there are, try to find the most recent. Going beyond that, if there was a technical issue, speak to the technical support people on ways to prevent another loss or if the loss was due to say, faulty wiring or an outage, find ways of making sure if the problem happens again to avoid it with UPSs or calling out an electrician.