Sun Droplet is not entirely correct:
T:Mode$ Phase | Phase$ Upkeep | ValidPlayer$ Player | IsPresent$ Card.Self+counters_GE1_CHARGE |
Execute$ TrigGainLife | TriggerZones$ Battlefield | OptionalDecider$ You | TriggerDescription$ At the beginning of each upkeep, you may remove a charge counter from CARDNAME. If you do, you gain 1 life.
This trigger does not actually have an "intervening if" and should trigger even with 0 counters. This has some edge benefits -- for example, with 2 Sun Droplets, you could use a painland in your upkeep to take damage with the triggers on stack and gain 2 life from that. Even with a single
Sun Droplet, there are many lifegain triggers nowadays.