This varies by sportsbook, some are very structured, and others are not.
DraftKings: One of the easiest sportsbooks to become a VIP. An email to their VIP team, email@example.com, saying you want to make a large deposit (over $10,000 most times) will get you an invite to the VIP showcase. DraftKings likes to see a minimum of $5,000 a week in wagers to maintain VIP.
BetRivers: They have the most structured VIP program. You get 1 point per $6 wagered, and once you reach level 7 you have access to their monthly VIP calendar. Level 7 is 5,200 points, which is $31,200 wagered a month. Their VIP calendar is often worth a few thousand a month.
Barstool: Emailing firstname.lastname@example.org asking what they can do for a deposit over $10,000 often gets you into their MVP program. Barstool looks for $10,000 in deposits every 30 days. They have a second tier of $25,000 a month in deposits.
Caesars: Like BetRivers they have a structured program. Once you reach Diamond a Caesars VIP rep may reach out to you. To reach Diamond you need 15,000 tier credits. You earn 1 tier credit for every $5 of potential profit on sports bets. With a maximum of 2 tier credits for every $1 wagered.
Most sportsbooks have some sort of VIP program but are less structured. The general way to become a VIP is to deposit and bet large amounts. Reaching out to the sportsbook before a large deposit and asking if there are offers available/details about their VIP program is a best practice.
Once you achieve VIP on a few sportsbooks it becomes easier to maintain VIP status because you will be hedging the VIP offers from one sportsbook against the others. This helps generate the desired bet amount, handle, sportsbooks want from their VIPs.
In addition to the VIP offers readily available, you can request additional offers such as deposit matches from your personal VIP representative. A method that normally works well is placing two very large bets against each other at a small loss. Then when one of them loses you reach out to the VIP representative on the losing sportsbook and ask for a deposit match. You can then keep repeating this strategy, continually cycling money and increasing profits.