Do you have any advice about entering multiple ES contracts?

So far, I have experience with up to 10 contracts. What could I expect with entering 20, 100, or more contracts?

My signal to enter is real time on the beginning of a minute bar, so, I enter at market with a few ticks of slippage.

I have 2 specific questions:
1) How to get the whole order filled?
2) How to reduce slippage?

These are methods I’ve read about.
• Market – take what you can get, at least you are “in”
• Limit (turn to market if unfilled within X seconds)
• Half at market now, half at market after a fill
• Scaled limit orders

Whenever I see this question I point people to the following thread, hoping it'll serve as an eye-opener

Experience with Slippage/Delay on ES S&P 500 as you increase contracts? Hi folks, I've heard rumors that slippage is a factor as you increase contracts on the S&P 500 Eminis, is there a level where that starts to affect my trades? 50 contracts? 75 contracts? And is there a level where I should start to look into other …