How to how-to
While we're on the topic of instructions that actually work, I have three more tips for you. Let’s look at this very normal example to guide us.
1. Defrost chicken until room temperature.
2. Put stockings, heels, and black corset on chicken.
3. Make chicken perform dance from Cell Block Tango.
4. Don’t leave sexy chicken on the kitchen bench unattended - if your housemates see it, they'll accuse you of being a pervert.
5. Undress chicken, put chicken back in freezer, and repeat steps one through five whenever you need a pick-me-up.
Aim for 3 to 5 steps
Okay, so this one won't fly if you're writing the instructions manual for a large, complicated piece of machinery. But if there are no gears or whirring cogs in the room, limit yourself to only 3 to 5 steps in your instructional set. This will help your instructee parse the information quickly and confidently. In the above example, the user can see that recreating the Cell Block Tango dance with a frozen chicken is possible in only five easy steps!
Don't be afraid to use negatives
Instructions are usually active, like “Do this, then do that”. But effective instructions take into account the most common blunders and misunderstandings a user will encounter and work to sidestep them. For example, I feel it’s very important to remind the user not to leave the chicken out on the bench otherwise your housemates will call you the Poultry Peeper for the rest of your natural life. Another example is this bandaid box.
They’ve designated "Skip the ointment" as its own step, as well as "Keep it on". Evidently, dumbass bandaid users slather themselves in ointment and tear off their bandaids before the magic healing gel has time to work and they need specific instructions not to do that.
Not all steps are created equal
My bad habit when writing instructions is to get really granular and create a new step for each individual item. This means my instructions end up with 42 steps and the first one is "Be born".
I used to think this was kind to the user, giving them all the information they could possibly need. Now I see it's kinder to group small, related actions together to a) make it easier for the user to comprehend the instructions and b) create a hierarchy of importance within the set. In the above example, defrosting the chicken is a relatively small action but gets its own step because it's important (a frozen chicken wouldn't be able to pull off some of the more acrobatic moves in Cell Block Tango). But the pack up, which consists of three individual actions, are grouped into one step because they're less important.
TL;DR? When writing instructions, stick to 3 to 5 steps, don’t be afraid to use negatives or warnings, and group or separate actions according to how important they are.