I lease sp for my three STEEM blogs, and have since I started here 2 years ago. Like you I realized I could grow my accounts faster with the leverage, instead of adding tiny amounts to sp.

But unlike you, I do not lease big. I lease many small instead. I lease:

• 50 sp for 24 weeks at 14.2% each time.

Then I renew when the leases come up. I do this so that I don't get hurt too much if someone pulls their lease, which they do sometimes.

So I usually have lease requests open in minnowbooster. Not now,since all three got filled this week.

Some tags to look at for good curation rewards are:
steemiteducation
steemhunt
esteem

If you get in before the curators of those tags do, you will get good rewards. You need to be good one finding the people who will later get the curation, but it is not that hard.