Upload a few hours before your traffic peak on the real-time graph.
That way you are positioning right in front of the wave.
Add the new videos to all videos cards to highlight it, and set it for "returning subs" and "new visitors" to see.
If you have a marketing budget, allocate $5-$20 for Adwords to it.
Share it across the web if you have an active engaged following somewhere hungry for your content, or you have identified other places your audience hangs out and are willing to hop over to Yt or watch it embedded.
Sometimes your can't see your videos within your 24 hour upload cycle. It may be best to upload every 2-3 days. Only way to know is to experiment, daily, 2 days, 3 days, see the stats.
That's the best way to give each video a chance to succeed.