How do I get something sticky like honey or Golden Syrup off measuring spoons or measuring cups? Is there a better way?

It's possible to get specialized equipment for this: a plunger measuring cup. The base is adjusted to the level you need to measure, the sticky honey or syrup is poured in, and then the cup is upended and as the base is pushed in, it scrapes the sides as it travels.

I'd only invest in this if you very frequently measure sticky ingredients -- it's not strictly necessary, but it can be a timesaver for some recipes. It's available from many different brands.

As, since this answer other suggestions have abounded, let me clarify.
These methods assume you want no wastage & also no cross-contamination of your source jar of the sticky component. They also require almost nothing in the way of 'extra equipment'.

Depending on what the next steps to your recipe are, I can think of three alternatives. None are perfect and each would suit a different scenario.

1. Tip it and leave it a long time.

2. Heat it slightly. Microwave or sit the container in hot water.

or my favourite,

3. Rinse it out with the next liquid ingredient you will use in the same recipe; or for a spoon, stir your existing ingredients with it.

Your concern is NOT getting the measuring item clean. Your concern is ensuring the right amount of ingredient goes where it is desired.

If you have decent accuracy digital kitchen scales (relatively cheap usually but may depend on your location), you can measure by weight.

If you need to determine the weight by measure of your sticky substance, start with these steps:

1. Place the measuring item (spoon, cup whatever) on the scales. Tare the scales to zero.
2. Scoop quantity of sticky substance. Measure on scales, and note the number.

Once you know how much the desired measurement should weigh (you can also look up these numbers online or in many cookbooks):

3. Place destination bowl on scales and tare to zero.
4. Add sticky substance up to the desired weight.

What I do, if the recipe calls for any sort of oil, measure that first, then the honey slides out pretty well.

It's not a perfect solution, but using two spoons and scraping one with the other you can get the majority of the syrup off the spoons relatively quickly.

Silicone spatulas are quite good at cleaning hard vessels well. Combine that with a small enough measurement - so don't measure 50 ml of honey in a 1000 ml cup, use as close to 50 ml as this gives you a better ratio of volume-to-wall-surface - then scrape with the silicone spatula, and it will be almost as clean as licked.

For getting the cup clean afterwards, wash with hot water, not merely warm.

Heat the utensil. For a spoon, fill a coffee cup with boiling water, and drop the spoon in there for 30 secs or so, or for a measuring cup, just fill it with boiling water before measuring out the honey/syrup.

The heat will reduce the viscosity making it pour off the spoon/out of the cup better.

I've found that a light spray of cooking spray on the spoon or in a measuring cup will make measuring any sticky substance very easy.

Rub a tiny amount of neutral oil onto the measuring cup prior to measuring.

Water on your spoon will help, I found that when I put peanut butter into my drink in the morning and used a wet spoon from the draining board that it is considerably less sticky.

Why not put the honey pot on the balance instead and take your measures at reverse? That's what I do.

Convert all measures to CC's and then use syringes. Different syringe for each ingredient. Minimizes waste, and they come sterile.

In the case of honey or syrup, buy a squeezy bottle, and measure out the amount by placing the receptical on a balance and squeezing until enough comes out. The bottle can be rinsed out and used again and again. I also buy glass jars of honey (much cheaper than squeezy), and decant that into the squeezy bottle.

Weigh everything that is sticky and messy. Measure the old way in a measuring cup than weigh it, write it down for next time. Of course don’t forget to weigh the cup empty first. Kitchen scales are very cheap nowadays.

Line your measuring cup with a bit of Saran Wrap. It's thin enough that it won't mess up the volume/weight by any significant amount. When you're done measuring it you can just pull the Saran Wrap out of the measuring cup and scrape the honey that sticks off with a silicon spatula. Even better, when you're done you just throw the Saran Wrap away and your measuring cup never gets dirty!