The order of operations matters more than any individual technique: most failures are the right steps in the wrong sequence.
1. Niche and offer
Audience you understand first, offer for them second. The reverse order works for experienced people and almost never for beginners.
2. Accounts and proxies
Two to five aged accounts, a proxy each, proxy country matching the number's country. Straight onto warm-up — it takes weeks and has to start before you need volume.
3. Building the base
Parse channels and chats on your niche keywords, then check them: alive, and comments open. Collect three times what you plan to use.
4. The approach
An opening message with a reason, one thought and a question. No link. Ten variants rather than one.
5. Launch at low volume
Twenty to thirty contacts a day per account in week one. The goal is measurement, not volume.
6. Measure and adjust
Four numbers by stage. Change one thing at a time. When the numbers hold steady for two weeks, you can grow.
What not to do
Do not start at volume. Do not put a link in the first message. Do not work from a personal account. Do not scale after one good day.
More on the approach on the traffic arbitrage page.