Think of it this way:
the Tools really are the diagrams you use
i.e. use case, class, state, erd, robustness, action, etc
There are alot of diffrent diagrams that are out there, all that can be used to model software.
The techniques are really the methodologies: how you USE the tools. For instance, some methodologies say that you need UseCases, ClassDiagrams, Sequence DIagrams, ERD's, etc.
Some say usecases, state, class, robustness, and sequence
The methodology is the map of how to use the various tools.
Now, with that said, there are other tools that are used to fine-tune the process:
-Software tools like Visio and Rational Rose
-Coding patterns and techniques like Class Factory, Facade, etc.
So the really easy, basic way to look at it:
Models = Tools
Methodologies = Technique
Of course, this also depends on what you do:
if you're a coder, then the coding patterns is going to mean more to you than the diagrams. If you're an analyst/designer, then the diagrams will mean more than the coding patterns, etc.
hth
Jack