Find a table and sit down. The chicas will approach you. The trick is getting the right chica
It doesn’t take much skill to get a chica to sit at your table. English, Spanish, and hand signs will all get a chica to come your table. So will asking a waiter to go get a chica you want to see.
The hard part is not getting scammed by chicas, waiters, etc. (Years ago, on another site, I posted The Newbie Guide to Tijuana with tips about such things.) Be sure to negotiate everything—price, time, services desired, etc.—before starting a session.
To avoid being scammed you need to understand many things about how the world goes round in TJ. One of those things is that bars only make money on the drinks sold. (They don't get a penny of what chicas earn for selling sex). So bars give chicas a daily sales quota and reportedly fine chicas who don't sell the daily quota. Chicas also get a commission based on the number of drinks they sell. (For each drink they sell they get a "ficha" meaning a ticket used to claim their commission at the end of the shift.) So everybody—the bars, the chicas, and the waiters—has a financial interest in getting you to buy a lot of drinks. Drink all you want, but don't get "ficha fucked" in the process. Meaning don't get pressured into buying drinks you didn't really want to buy.