Useful rule
Occam's razor is the forerunner of the KISS principle. The KISS principle has become the hallmark of good engineering. The problem with this is that no matter how well Occam's razor/KISS has been applied, we still have to deal with Murphy's Law which is inevitable and immutable.
The simpler explanation is the usually the better choice. Of the least complicated set of assumptions is more often correct.
The simplest solution to a problem is usually the best one.