The PIC determines his own traffic pattern at an uncontrolled airport.
And what does being the PIC mean to you exactly? Certainly would you include common sense, using your best judgement,
following procedures, situational awareness and doing what is safe?
To land safety in a non-towered environment you rely on predictability. That’s why patterns exist in the first place. At an uncontrolled field that has little to no traffic on a regular basis, there should be little problem with going straight in or other non standard approaches
provided you announce your intentions and relay continual position reports
and there is no conflicting traffic in the pattern or on the field. Period. Under a busier environment, the standard pattern should be adhered to at all times
in addition to announcing your position in an effort to maintain a safe and smooth flow of traffic.
You should also tune in the published radio frequency of the airport and determine which course of action to take dependent upon the level of activity you hear on the frequency. By listening and looking for the number of airplanes you see approaching and departing, your good judgement should dictate whether or not a non standard approach would be acceptable. And, if flying the pattern you should check that final is clear before turning from the base leg. This is basic airmanship.
Being a PIC means doing what is sensible, safe and correct. It doesn't mean doing whatever you want to/feel like with no consideration of other variable factors or the traffic around you and it doesn't mean breaking the rules for your own personal desires or making foolish choices. Control means you know exactly what you are doing and what the circumstances and traffic around you is, including on the ground. Every situation and every landing is different. Know your environment and choose based on that environment. Doing the unexpected, not communicating, not planning, not being aware (SA), making bad decisions and not following procedures at some point, is not going to end well for you and possibly others.