Method - refers to specific type of population conduction that you will take to achieve your objectives and is very dependant of mating type (Allogamous or autogamous plants);
Techniques are what methodologies you will use - e.g., self fertilization, crossing and the paths involved in each one;
Strategy - well how do you reach your objectives and what are they. Are they achievable? By means of what method? So, it is your planning before starting.