Agencies  are also good but the big thing is to create your  own pieces and discover your own individual style . Producers are at many events and festivals and therefore these places are perfect to get your small plays investment and on to a big stage.
create a list  Skills that could have an influence on you getting a part over someone else. trates that are positive and saying your weaknesses are something positive e.g- i always have to finish something once i have started.