UPDATE 3: As of December 19, 2016, in a suprise turn of events, Pixiv has decided to revert the layout back to the old design for good, putting an end to the new layout. This decision was made after listening to fan feedback. With that in mind, the previous two updates are now null and void. You can skip right to the article proper now.
UPDATE 2: Recently Pixiv enabled users to freely switch between the old layout and the new layout. The old layout retains all of the old features, including stars and bookmarks (which the new layout consolidated into "Likes"). Unless Pixiv nixes the old layout for good in the future, everything in this entry refers to the old layout. Several parts will still apply to the new layout as well.
UPDATE: As of October 20, 2016, Pixiv has made a major overhaul to their site's layout. This also means that some feature have gone missing. At the moment, New Work: Everyone is no where to be found. This also means that the Pic Speed is missing, which might make it harder to gauge when peak time has started. I'll give it around a month to see if any of these are reimplemented and will ammend this entry accordingly. None of these changes has impacted the tags.
When uploading artwork to (or just browsing) Pixiv, it’s best to use Japanese tags (as mentioned on their Help page). Use English tags only if the romanji is what’s most used and recognized anyway (like VOCALOID or Overwatch). It’s also best to use tags that have the most use (evidenced by the result number). The only exception to the rule is title tags. For example, take games like Lords of Thunder or 魔天童子 (Matendoji, the Japanese title for Conquest of the Crystal Palace). While they’re obscure games as far as fanart is concerned and yield little results, use them anyway. You never know if fans might be around looking for fanart, or outside fans start wondering what game that piece of fanart comes from. There are tags with multiple ways to say it, like boobs being おっぱいor 胸. If stretched for tags (10 allowed, 9 for R-18 since one of them is “R-18”), use the one with the most results.
