Creating an amazing finish is something that many people want on their outdoor furniture. While creating one is not terribly difficult maintaining it can be. For one that truly stands out in comparison to others you will also have to do quite a bit more work. It all comes down to what you want from your setting so keep it in mind when you are looking at your options. And of course you can always have someone do it for you if you lack the skills, or the time, to do this for yourself.
Before you get started you can always looked into options where the manufacturer has finished it for you. While these are often of good quality because this is how they make their money you have to remember that they make their money in this manner. As such you will probably be paying quite a bit more for this when it happens. If the time you save in this area is worth it to you then go ahead with this.
Working on outdoor dining tables provides a great example of what you will need to do. First you will need to sand off any edges and wax it properly. You may need to even paint it before that if it has already been damaged. Then you should coat it with a layer of sealant which knocks water away. Afterwards there are other treatments you can do which may or may not be necessary depending on the level of damage and what your weather in the area is like.
Unfortunately even with all this done you will still have some damage to it over time. As such you have to keep tabs on it and re-apply these in order to make sure it stays looking good. If you are lax with it then you just wasted all the work you did before. Only the very rich can afford someone to look after this. Insects and wildlife can also do additional damage to it if you are not careful.
On the other hand you can actually do too much work and make the finish on your furniture slick. It should be pretty clear to you why you do not want a slick outdoor dining table. Unless you have some very unusual dinner guests this is something that you absolutely have to avoid at all costs.
Another question is whether you want to put a finish on these at all. In most cases the answer is yes because so many different tables look really good with it. In a few rare cases in which you are going for a weathered look you would probably want to leave it as-is. In other cases a wood naturally has a grain which is absolutely beautiful and you want to preserve this as much as you can by not working on it too heavily. In either case you could have a good reason to avoid this and just let nature take its course in weathering it down.