Ok the way I worked it out was from a table that had a list of all the possible effects.
I noticed the ones that where there was extra water (e.g. in burette/pippette/Volumetric flask (e.g. deliquescent standard, or overshot the mark), etc) all resulted in the same result - if it was the known, it increased the concentration. If it was the unknown (obviously not the volumetric flask though), it would decrease the concentration.
Strictly speaking, dilutions will not effect your result - unless you are using volume to calculate. So diluting a conical flask has no effect.
Now the assumption is if you have same volume, more water, this lowers the concentration. The inverse is true as well. More moles, less water, higher concentration.
Now if you have a lower concentrated unknown, you'll work out a lower concentrated unknown. You have a higher concentrated unknown, you'll work out a higher concentrated unknown. Simple as that.
If you have a lower concentrated known, this means MORE is needed. hence you'll work out a higher concentration of unknown. This is the hard one to get your head around with. Basically it would be the opposite.
So dilution, but keeping same volume = lower moles delivered.