Lab tech had research project that is now being developed by honours student: Who deserves to be first author?
There is no general rule on how you determine the order of authors. In some areas (like Mathematics, for example), the order of authors does not imply the relative size of their contributions --- it is typically alphabetical. This strategy has its benefits: for example, we are less likely to include "star" and "virtual" co-authors, because there is no way of distinguishing them from real ones. And of course it simply saves time and helps to maintain good relationships.

In some areas, the contributions of each author are explained at the end of the paper (e.g. "data collection: Dr A, Dr C; statistics: Dr B, Dr C; visualisation of results: Dr A; writing the manuscript: all authors"). 

If neither of the above helps, the best way to handle author ordering is to discuss it before you start working together. Definitely, by the stage you have your first draft everyone has to agree on this, and no last-minute changes can be done without full and active consensus.