Not everyone is a beauty editor blessed enough to receive daily bagfuls of samples of products to test, play with, and write about. You’re living on the realway, not the runway, and you’ve got limited expendable income. The shelves of Sephora teem with drool-inducing products that you want, and let’s face it, need. There’s no shame in that. But wading through the bottles, jars, and pretty packages is an ugly and stressful business. You are faced with tough choices. It’s nearly impossible to sort through the ether to find out what’s really splurge-worthy, what to indulge in, and what’s better picked up at mass market discount stores that also sell clothes, TVs, baby food, or candy, like Target and CVS.

There are four simple golden rules to apply when wrestling over whether or not you can justify the spend on, say, a bronzer brush that comes with a $78 price tag because it boasts the Marc Jacobs logo on the handle. Of course, you’re allowed to make exceptions every once in a while. Did I need the aesthetically pleasing but not at all practical NARS x Andy Warhol Flowers Eye Shadow Palette? Definitely not, but you can bet I still dropped some cash to add the collector’s item to my makeup bag.

The next time you’re going back and forth on whether or not to splurge on the latest Tom Ford lipstick or Chanel foundation, refer back to these four rules. These simple, foolproof guidelines are all you need to make decisions on the thousands of products out there.

1. BE WISE ABOUT INVESTMENT PIECES

Yes, an expensive item is expensive is likely of a higher quality than a drugstore version, but that doesn’t meant it suits your needs, your life, or your budget. So ask yourself this and be honest with the answer: Will this item pay for itself? That is, will you use it daily? Will the cost-per-use be nominal in a year’s time? Will it last for five years with proper use and care? Does it end up being pennies-per-use because you utilized it over and over and over again?

If the answer is “yes,” then it’s okay to debit your bank account by nearly $100 for the aforementioned Marc Jacobs brush, which I would use for powder foundation, not bronzer, making it even more valuable as a multi-tasker and thus worth the spend. The difference between how good or bad an inexpensive product looks on your skin can be the tool with which you apply it. You can save loot cakes and perhaps use a mass market foundation — the kind that won’t require you to don a breathing apparatus if you drop it, it cracks, and is rendered no-longer-usable — if you apply it with the Holy Grail of brushes.

2. CHEAPIES ARE DEFINITELY OKAY FOR TRENDS

Trends, by nature, are not meant to last. They are here today, gone tomorrow. Therefore, the logic is that you don’t need to drop $50 on a product that will be off the Sephora shelves in six months.

Mass brands will always have their trendy alternatives. They’re a safe bet when you want to grab “now” shades and not stress when they go out of style and you have a half a pot of product left over that you’ve now decided you won’t be caught dead in because it’s so 120 days ago. You won’t feel guilt over tossing a $2 glitter-loaded shadow when it’s no longer in vogue. Or in Vogue. Plus, if you splurged on a good set of tools, that can be the difference-maker when it comes to getting these products to “work” for you in another capacity beyond their trend shelf life.

With skincare, it’s acceptable to shell out a few extra bucks for high-end, luxe products. But at the end of the day, it’s all science and everyone’s skin reacts differently to the cocktail in the creams and lotions. Try out samples of the high-end ones and the cheapies to see which works best for you.

It’s okay to play with celeb-backed brands, too. Salma Hayek’s Nuance line at CVS is vast, with the range serving hair, skin and color needs. The color products are somewhat “meh,” IMO, whereas the skin and hair items are of terrific quality without requiring you to skip lunch (and maybe even dinner) in order to pay for them. I’m partial to the Glycolic Cream Cleanser, which offers light exfoliation through slightly invigorating and gritty texture, and an overall refreshed feel when I use it, and the Healthy Shine Nourishing Oil, which adds moisture and gloss to my hair. It’s like a budget Moroccanoil. Same result, but less wallet damage.

3. DO YOUR RESEARCH

Pay attention to what your favorite style stars or publications are saying about products. I routinely remind friends and readers that Rimmel’s Exaggerate Liquid Liner is the single best product to achieve the cat-eyed look and it costs $7, at most, at CVS. There are so many black liquid liner alternatives out there and trust me, I have tried them all in my quest for rock chick eyes perfection. I have dropped $40. I have dropped $5. Nothing works like the Rimmel liner. If they ever discontinue it, I will require multiple sedatives and will never forgive Kate Moss, who reps the British brand, even though she has nothing to do with these decisions.

4. KNOW WHAT YOU LIKE

I am a huge fan of Jennifer Aniston and her flawless coif, so when she FINALLY teamed up with Living Proof for a line of hair products, along with her stylist Chris McMillan, who also gave the ever-topless Miley Cyrus her infamous chop, I knew I would be trying out the products. There was no way I would not splurge for these. If they were good enough for the flawlessly follicled Aniston, then bring it, when it comes to me.

The products are pricy, but they work. I used to use nary any product until I got bangs and I needed an anti-humidity thickener. The Living Proof thickener, which smells like pink pepper, requires just a dime-sized dollop to keep my bangs are full and perfect throughout the day, regardless of weather conditions. I also use the primer and the dry shampoo. These are my splurges and I use every drop. If they didn’t work, I’d have moved on, despite my unhealthy obsession with Aniston hair.

But the main point here is this: Since I am saving with my dirt-cheap Rimmel liner, I can splurge on these Aniston-approved hair helpers! See how beautifully that works out?

So essentially, don’t simply buy something because it is expensive or because it is cheap. Buy it because you know you will use it a lot. Exploit cheapies for trends. Do your research. Know what you like. Boom. You’re done. And you’re welcome!