Rinse your cucumbers and wash about 8 jars. Drop a garlic clove or two into each jar, and a few large dill fronds. Pack the cucumbers snugly into the jars, starting with the bigger ones and filling any gaps with the smaller. (You could also do spears - cut them into quarters lengthwise, then put the cucumbers back together before packing into jars to keep them crisp.)
Meanwhile, bring the water, vinegar and salt in a saucepan to a boil over medium-high heat, stirring until the salt dissolves and the mixture turns clear.
Ladle the hot brine over the packed cucumbers, leaving a 1/2-inch headspace. Process in a boiling water bath canner for 10 minutes - I of course didn't read this part fully, and put them in for 10 minutes and then took them out, but Amy says to start timing when the water in the canner returns to a full boil. When the processing time is up, turn off the heat and remove the lid. Leave the jars in the canner for 5 more minutes.
Let them cool - you'll hear the satisfying pop of each lid as it gets suctioned down, showing that it has successfully sealed. (If it doesn't, store it in the fridge.) If you can manage, wait 3-4 weeks before you crack one open.