Is traveling alone more expensive?

Not having anyone to share the cost of accommodation, eating a typical dish, or other occasions leads many people to conclude that traveling alone is more expensive. But in practice, this isn't quite the case.
The ability to do things your way also includes deciding how or where to spend your money—which, when traveling in a group, often doesn't happen, since most people decide how it's going. And suddenly, we're doing the expensive thing our friend wanted or going to the trendy place we don't even like just to avoid creating a bad atmosphere.
Because it's also annoying to be that person. I've ended up paying more for trips with someone else precisely because I gave in to the temptation to displease them. Naturally, we end up paying for things we wouldn't have paid for alone. A fancier place here, a little extra expense there, an unplanned outing somewhere... and an unexpected bill on my credit card.
When I'm alone, it's much easier to stick to my plan. I always do a lot of research on the destination, try to plan a pre-planned itinerary, calculate my average daily budget, and then adjust accordingly. If I've had lunch at a more expensive place, I'll just have a snack at night. If I've stuck to the basics during the day, I can afford a little more.
I think this planning is essential because when we travel loosely, without anything planned (which is also great in many ways), there's a greater tendency for unexpected events to occur, which usually lead to more expenses. Of course, you don't need to stick to a rigid itinerary, but it's good to have a set limit and some extra money, because nobody's made of iron.
Around here, I just don't save much on accommodation. This is essential for me. And being in a safe, well-located place has its price. Of course, within that, I choose what fits my budget. But opting for more remote places just because they're cheaper is the old "cheap that ends up being expensive" thing. It's not worth it.
Some practical tips I've already shared on my blog, Mariana Viaja, and on Instagram @marianaviaja that also help you save money when traveling alone are: always have something to eat in your bag (bring it from home or buy it at the local market); prefer to try typical foods at stalls or cafes with more affordable versions than famous restaurants; ask the staff for recommendations on where to go because locals always know better options; check out the free tours.
List your priorities and choose what's worth it so your itinerary fits your style - and fits your budget!