A reader shared this question with me a few hours ago, and it was an interesting conversation today followed. The important thing to keep in mind is that given that the collagen content naturally changes as you age, and then it decreases to the rate of between 1.5% and 2% each year your skin is going to need some external help.
You could take a collagen supplement to assist with this. However, the quality of this type of product needs to be evaluated. I would suggest looking at seaweed as a means of collagen for a couple of reasons; it assimilates into the body very effectively compared to animal collagen, and it's very flexible in how you can use it.
Stay away from seaweed that has been baked as this is effectively dead. You want to choose a seaweed that has been dried without baking that you can soak, wash, and rehydrate into a supple form that you can then make a gel from. For instructions on how that can be done see Collagen for Vegans – Can You Get Collagen From Seaweed? which will walk you through how to fo this.
Don't be put off by the smell initially, with a few washes and soaking this will go away. You can use the gel as a digestible source of collagen, and you can use the gel as a mask to get the collagen directly to the skin.
The challenge with consuming collagen with the goal of younger looking skin is that it takes a long time to have this effect. The body will naturally use what you give it for life supporting functions as a priority, and younger looking skin comes a fair way down the list from healthy, functioning internal organs.