Know the key difference between using “phrase” and broad adwords keyword match types when bidding on a single keyword.
Sometimes it might be better to leave competitive single keywords on phrase (i.e “plumber”). Broad match could trigger synonyms (i.e pipe fitter, craftsman, artisan, journeyman, artificer). Try to use broad for research (like a live keyword tool) and refrain from going “all in” with investment if all your doing is getting results without knowing how you got there – adwords is not a miracle and campaigns need optimisation; the process of improving how to get to conversions. Identify navigational, informational and transactional search queries or start with transactional on small budgets.
Could install a conversion tracker and study conversion paths to then make strategic bidding decisions as opposed to not knowing what you are bidding on.
Heavily research keywords before starting campaigns and ensure the right match type is always used. This time consuming process you to measure conversions accurately.