While Toastmasters has a long history, its Pathways educational program fits the current thinking about mastery.
There's a notion that you need to have practiced something for 10,000 hours before you get good at it. Writer Malcolm Gladwell made the idea popular, and writers indeed spend that kind of time honing their trade. Spelling and grammar are just the basics: The only way I could get beyond them was to write, and write often. Working on deadline took practice, but once I met one deadline I became more confident I could meet the next one.
Public speaking takes practice too, but not 10,000 hours worth—or 10 years, if you figure three solid hours a day. Honestly, it doesn't take that long to see results. It does take an audience, but few speakers have logged 10,000 hours in front of a crowd.
Gladwell gets a lot of heat for his 10,000-hour rule, but those who've studied the idea agree with at least one facet of it. Practice will lead to mastery if it's deliberative. That means learning the elements of a skill, taking time to focus on those building blocks, and keeping at it without getting discouraged or burning out.
Amateur speakers have used those three steps for years to practice speaking in YMCAs, church basements and conference rooms. Toastmasters clubs all follow manuals that present the skills in sequence. Members work mindfully on each skill, and the audience gives feedback to improve. One skill bulds on another, and with practice they all come together. So while Toastmasters has a long history, its program fits the current thinking about mastery.