Hi Lawrie and welcome to TP
As
@Bebop says, what you describe IMO is the most common question in regard to printing. As she says and I agree, if you want consistent prints and control then a monitor calibration device is a key bit of kit.
However, you can get a very good basic "calibration" based on the human eye being in control by using the tools on this page
http://www.lagom.nl/lcd-test/ to check your monitor setup. So do give that a go and then see what a test print looks like compared to what you have been seeing!
But the use of a calibrator takes the personal human variations out of the equation.