Any tips are welcome

There is a French nail hardener which is usually available in department stores. I have used it sometimes back and it hardened my nails. Look for it in department stores or beauty stores. It cost much more than regular nail polish but you will definitely enjoy the results. It comes in three colors; clear, white and pink. The white and pink is used for French manicure/pedicure.

I've had the same problem. I can't keep my nails long because their very thin. They tend to bend too easily and they tear like paper instead of break. I've tried a lot of products. It has been a trial and error for me. I've spent a lot of money just to make my nails strong and long. I found Sally Hansen's Hard as Nails base coat to be very effective. The product is flawless when applied. You can use it alone or as a base coat with any color you want. It dries really fast and is cheaper than the other Sally Hansen nail treatment polishes. I've tried another Sally Hansen product which is way more expensive than Hard as Nails base coat. It's the Sally Hansen Miracle Nail thickener. It's very nice, but I'm not really sure if it's effective enough as I haven't been able to use it as prescribed, but I don't like the product's consistency. The product thickens fast which results to streaky application. The most effective I have ever tried is the most inexpensive of all. Try putting minced garlic in a regular clear polish. What I did with mine is I extract a little garlic juice and put it in my clear polish. I even added minced garlic to enhance the mixture. You can use it after 7-10 days. It's stinky, yes. It's very smelly when applied. But the scent goes away after less than 24 hours. It improves the clear polish's shine. You'll notice that the product is shinier than before. When applied regularly, you will have a set of very strong nails and you will eventually get the long nails you've desired. They're even as hard as acrylic extensions. You will see the results in as little as 2 weeks.