Decisions can be emotional or logical.
There are basically two types of decision making. The first is objective or logical or quantitative(using numbers). The second is subjective or qualitative(not using numbers). The goal is to a make any decision making as objective as possible. There are times when an objective decision is not possible. An example of this is coming to a fork in the road while driving. If there are are signs that communicate where each fork is going, you can make an objective decision. If there are no signs and you have no knowledge of where the forks go, then you must make a subjective decision. Which way seems like the best way to go to get to my desired destination?
All important decisions should start with the basics as described in Decision Making Model In Five Steps. This will lead you into an objective type of decision making. It is always the prefered, of the two types of decision making. When you have defined the alternatives, the next step is to chose a methodology that will help you make a decision between the alternatives.
Objective decisions apply a numerical or logical method for making a decision. A financial decision might use the criteria of finding the least cost alternative. Using the NPV Calculator on your alternatives would give you concrete numbers to make comparisons between your alternatives. Another approach combines small subjective decisions to make an overall objective decision. You can try it out at Example Of A Decision Matrix. A third approach used by many large corporations is illustrated at Example Of SWOT Analysis.
The key to making a good subjective decision is to make your subjective judgements on very small increments of the total decision. Your ability to make small simple judgements is much higher than your ability to make large complex judgements. When you rate your subjective feelings and opinions, by putting numbers to them, you make your subjective decision as objective as possible. You can see how this works at Example Of A Decision Matrix
Whichever of types of decision making you use you want it to be as rational and objective as possible. Rational means that is well thought out, logical and deliberate.