With offers of 50,000 points or more, credit card sign-up bonuses can be highly enticing. Savvy consumers use these bonuses for rewards-funded vacations that would otherwise be out of reach. The process is simple: You apply for a credit card, meet the spending requirements and receive a substantial welcome bonus. But how big that bonus is and how often you can repeat these steps depends on several factors.

With some banks restricting this highly lucrative practice, it’s more important than ever to make sure that you get the highest offer possible when you apply for a credit card. Here’s a look at six simple ways you can secure bigger credit card sign-up bonuses:

1. Understand each issuer’s rules

When it comes to scoring the best credit card sign-up bonuses, it’s important to know the rules governing approvals with each issuer in order to receive the best possible offer. Most of the major banks have implemented rules restricting credit card approvals. Some issuers, most famously Chase with its 5/24 rule, limit the number of applications you can have in a certain time period, while Amex has a once-per-lifetime rule that only allows you to claim a welcome offer on a credit card once, even if you apply for the same card many years later.

As you can imagine, these are pretty big incentives to make sure you time your applications right to get the highest bonuses possible.

2. Sign up to receive offers from an issuer

Getting marketing emails is a huge hassle for most people, but in this case, it could work out to your benefit. Sign up to receive offers from issuers and loyalty programs you’re interested in and you could get targeted for some pretty incredible sign-up bonuses.

It’s not unheard of for people to receive significantly higher welcome bonuses via emails and mailed flyers, sometimes even double the public offers.

3. Use Bankrate’s CardMatch tool

If the idea of getting more emails and flyers doesn’t sound appealing, you can opt for Bankrate’s CardMatch™ tool. Simply fill out a brief form and you’ll be matched with the best credit card offer for you. The nice thing about this is that you’ll receive a customized card recommendation based on your needs and potentially also offers that are significantly higher than the public offer.

For example, when the welcome offer on The Platinum Card® from American Express was 60,000 points, people reported being targeted for 100,000-point bonuses (or higher) through CardMatch.

4. Pretend to book a trip

This tip mainly works for hotel credit cards and airline credit cards. When you go through the steps of booking a hotel stay or airfare, you may notice an ad at check-out that promises to reduce the cost of your booking if you sign up for a co-branded credit card.

When booking a hotel stay, you’ll often notice a welcome offer on the check-out page offering a statement credit of several hundred dollars in addition to bonus points. These offers can be great for people looking for instant savings because it often takes time to meet bonus spending requirements.

Before applying for one of these offers, be sure to compare it against the public offer, so you’re getting the biggest bonus possible.

5. Scour the web

Sometimes a bit of sleuthing can pay off significantly. Sites like Reddit and Flyertalk routinely list credit card sign-up bonuses that exceed those that are publicly available. A quick Google search for the card name and “all-time-high sign-up bonus” might turn up offers that you wouldn’t otherwise come across.

Eagle-eyed community members frequently update FlyerTalk and Reddit threads. Keep an eye on these forums and you might just come across an offer that covers your next vacation to Hawaii. (Just be aware that if you apply with a link targeted to someone else, you may lose out on the sign-up bonus.)

6. Get referred

Sometimes credit card companies save the best offers for existing customers and their friends or internal referral channels. Referral bonuses cut down on marketing costs and incentivize existing customers to get the word out about their favorite credit card. If you’re looking to sign up for a specific card, ask an existing cardholder to send you a referral. You can compare that bonus against the public offer and possibly come out ahead. Even if you don’t end up with a higher offer, you help a friend earn a referral bonus.

The bottom line

When it comes to credit card sign-up bonuses, you don’t just have to take what you’re given. Maximize your bonus potential by doing your research to find the best offers. (There are some for 100,000 points or more, but they aren’t always worth the trouble.) Make the most of online forums and friends. And seek out targeted offers through issuers, Bankrate’s CardMatch tool or by going through the motions of checking out with a hotel or airline. Also, keep in mind that credit card sign-up offers change often, so if you’re interested in a particular card but not blown away by its current offer, it could be worth your while to wait for a better one.