The very common adjective successful is most often used to talk about the attainment of goals or wealth, as a successful career or successful entrepreneur. The synonym fruitful describes things that are or have been highly productive, particularly discussions, collaborations, or intellectual efforts that are constructive or that promise to yield fruit (the metaphorical kind) in abundance. May your writing be fruitful!
The verbs start and commence both describe beginning something or setting something in motion. But the more formal commence is typically reserved for beginnings of a particularly momentous and elaborate sort. Things that are commenced, such as ceremonies, legal proceedings, and commercial operations, are involved and often procedural. A commencement ceremony, though it takes place at the end of an academic year, marks a beginning of a new chapter in life. While commence is a fair alternative to the verb start, it may come across as affected and stiff outside of formal contexts.
In the most general sense, to use something is to employ it for some purpose, the way one might use a fork to eat spaghetti. However, when it is people rather than forks being used, this familiar verb takes a sinister turn. Here we find the synonym exploit. To exploit someone or a group of people is to take advantage of them in an unfair or unethical way. More often than not, exploit implies selfishness and mistreatment—often with a singular focus on profit. However, in highly competitive fields, such as sports and business, exploit may be used in a way that suggests cleverness in making full use of something, such as a competitor's weakness or potential market opportunities.