With plaisure. You just have 5 tags and you have to make good choise.
What I will say is just my point of view, probably there is better to do, I don't already discover it.

• Use the external site Bescouted.com by Hive account@bescouted (or David for VIP) with your steem key for posting. Just one picture by post, but you can have the curation of the owner (maybe 0.10$) Just put 4 tags in Bescouted, the first is for them.
• Go to the Hive account@juliank and you will see how to tag your post to participate at his contest (for exemple #landscapephotography could be nice for your post)
• The Art Tag is not pertinent for me, maybe you can use the photofeed tag.
• Same for the photocontest tag. Witch contest? Nobody know, you have to find the good tag for the good contest.
• Ok for the photocircle tag, but if you find better use it.
• For finish I don't know if the vietnam tag (vn) have a good popularity, maybe you can try with the travel tag

I hope you understand my poor english, ask me if it is not clear :)