No doubt YouTube is the most popular and the best video sharing website. Just stuffing keywords doesn't help you if you want your videos to be watched. Let's know why.
Keywords placement is useful only when they are being used to search in Google. Didn't get me? Okay, Samsung recently released their Galaxy S5 and every tech blog know that 'Samsung Galaxy S5,' 'Galaxy S5 specifications and price' will be the best keywords because users will search for S5.
In the same way, can you make sure that the keywords you used for your videos are the most searched ones? No, you can't. So, instead of depending upon keywords stuffing and tags, rely on content. Yes, content.
'What is your video about?' will be the first question a user asks himself on seeing its thumbnail. If it is interesting, unique, engaging or at least entertaining. Tell me who in this busy world wishes to watch nature's beauty? (I do) I'm not putting you down, being a publisher you should know what your audience like and what they're watching everyday.
Research, revise and get some cool videos in the niche that your target audience are interested in. No one likes long videos, so make videos that are less than 5 minutes with best quality. Also, make sure that your channel gets more exposure, you can do this by social promotion and local promotion (offline). Use perfect tags and titles for them. Don't forget to demand(request) a subscription or share at the end.
Hope you got my points.