Amberly Grant resides in Longmont, Colorado.Courtesy of Amberly GrantAmberly Grant achieved 'coast FIRE' by increasing her income and investing the excess.She maxed out three tax-advantaged accounts: a 401(k), a Roth IRA, and an HSA.She prefers investing in index funds because they're diverse, low-risk, and hands-off.When Amberly Grant came across the financial independence, retire early (FIRE) movement in her mid-20s, she bought into the concept but didn't know if she'd ever make enough money to participate."I had the tools, but I had no resources.