Running

Ask for what the PCs intend to do, not results. "I reach for the rope" is better than "I pull the rope up".

When a PC wants to act they must explain what their pc is doing, RP, or otherwise justify the skill check, otherwise they have disadvantage on their roll. (Use disadvantage sparingly, esp at first as PCs get used to the system)

If multiple PCs can are involved they all must make a check before another can take a second check. This simulates "rounds" in combat and prevents one PC from doing many things at once.

If a PC attempts to go twice before all have gone once, then it is at disadvantage. This rule should be flexible, since many times it will make sense for a PC act more than others. This rule should be the default unless the PCs can explain why it makes sense.

If the same skill is used twice in a row this is also disadvantage. This should be used regularly since it encourages the PCs being creative though you can skip this if the situation demands it.

Starting conditions

If the starting conditions are contested, have the PCs roll three checks against the passive DC of the target. The same rules for multiple skills/players and disadvantage applies.

3 pass = easy, 1-2 pass = moderate, 0 pass = hard