The most common are raising interest rates and selling securities through open market operations. (thebalance.com)
Firstly, it can buy or sell securities outright, which is the textbook description of open market operations. (rba.gov.au)
When a central bank changes the overnight rate but banks don't adjust the rate they lend to one another, the central bank engages in open market operations to ensure that they do. (wheredoesallmymoneygo.com)