Making preserved lemons is simultaneously one of the easiest/most tedious edible gifts you can make. Unfortunately, they take about 30 days before they're ready to use in cooking, so if you want to throw some together, you'll have to include a note with your gift that mentions they'll be ready to use in about February (LOL). I received some a few years ago and the flavor was amazing...just a little sliver could make Moroccan chicken, lemon orzo and other dishes taste incredible.
Here's what makes it tedious: the lemons work best if they soak in salted water for three days, with the water changed each day. Also, your jars will need to be sanitized.
Once they've fully soaked in their brine, scrub them and cut them into four wedges, only cutting halfway so the lemon is still attached together. Be sure to take juice one lemon for reserve juice.
Pour kosher salt into the lemon and rub it on the outside.
Squish the lemon into one of your sanitized jars (I used a Weck jar I bought at World Market...make sure your jar has a rubber barrier. The citric acid can corrode metal lids), making sure the lemon juice comes out. Repeat until the jar is full, and top off with reserve lemon juice and salt.
And that's it! Now, just let them preserve at room temperature for 30 days before use. Occasionally turn the jars upside down. The lemons make a great gift, but be sure to include some ideas of how to use them!