How much notice you're legally required to give before raising rent varies by state and by lease type, and this isn't legal advice, so confirm your specific requirement before sending anything. What follows is the general practice that tends to work well regardless of the legal minimum.
Give more notice than the legal minimum. Thirty days is a common legal floor, but a tenant who finds out they need to plan for a higher payment or a possible move with only thirty days often feels ambushed. Sixty days, where practical, gives them real room to plan and reduces the chance they leave out of frustration rather than genuine unaffordability.
Put it in writing, formally, even if you also mention it in person. A text message is not a notice. Use a written letter or email that states the new amount, the effective date, and references the lease. This is also the document you'd need if a dispute ever came up.
Explain the reasoning briefly. You don't owe a tenant a justification, but "property taxes and insurance both increased this year" lands very differently than a number with no context. A brief, honest reason reduces the chance a good tenant leaves out of principle.
Time it around the renewal, not randomly. An increase that arrives with the lease renewal reads as normal business. An increase that arrives out of nowhere mid-lease, even where legally allowed with notice, reads as aggressive and damages trust with a tenant you may want to keep.
Know what you're actually solving for. If the real goal is market-rate rent, decide whether that's worth risking a good, reliable tenant over. A slightly below-market rent from someone who never misses a payment is often the better deal.