I always liked using the Custap Berry.
Causes the holder to go first once when HP falls below 25%
So between 1% of the HP and 25% My Pokemon will get priority that turn. I use this in tandem with Pokemon who can abuse Spikes and have the ability of Sturdy. If I send out a Pokemon with full HP and its Sturdy activates I can get down at least two layers of Hazards.
For an example I will provide a Pokemon that I have recently been using in UU.
Crustle @ Custap Berry
EVs: 44 HP / 252 Atk / 212 SpD
- Stealth Rock
- Stone Edge
I use this as a suicide lead and it works. It's job is to get SR first and foremost and Spikes next. It can also come out on Chandelure with Stone Edge for a kill with a strong attack.