>>962
1. Must be a kanji in common use
2. Each kanji should be around 12-15 strokes at the top
3, Starts with the letter other than M, T, S or H in Romaji
4. Avoid the word as best when it's already high up in poll rankings among public
5. Not commonly seen in people's name
6. Not in the name of major companies

These are the conditions of 新元号. There's been clearly a trend that a letter that has peace or beginning in it was preferably used for the last couple of periods.
But it seems most of them are reference from some sort of old scriptures. I never read them, and I have no intention of going through them just to make a prediction so I'll just go with 永華 in that it's not in the rankings.
Also, prosperity comes after beginning, and most of all, it is something we all are hoping to see in a new era. We don't need peace. We need money.