[RichardA]

pencil -- easy to remove but stays put until then. Always do a  back up sketch. I have told this story before but many years ago when I worked away a lot the weekends were all I had for my garden and my growing family's hobbies etc. Good Friday to Easter Monday was kind to me that year and I got a lot done including about 40 small rows of salad, onions, radish, seed rows for cabbage, cauli, kale, leeks, sprout plants, etc for planting out later, herbs, even some seed rows of  flowers for transplanting. All labelled and all about a foot apart, parallel to each other alongside a path. Looked a real picture of effeciency. Watered the lot -- Went to work Easter Tuesday --- back the next Friday.
Daughter who was about 5 at the time had pulled up every label and played Postman Pat with the row of slightly open cold frames posting a few labels into each one until all 40 or so labels were delivered.
It is a good way to learn what emerging seedling leaves look like !!!!!!!
So as I say do a backup sketch.
R

[hightide]

strips cut from ice cream tubs!
 
mmmmmm W*lls Cornish
 

Only need to use a pencil on them and just for labelling contents of seedtrays and inserts. I use a spreadsheet; just make a layout of the plot to record what goes into the ground where and what variety. It is then easy to keep records for each year as a handy guide on what was successful and it keeps me right on rotation.

[Brambles]

One of my DIL's uses permanent marker pen on nicely shaped stones... They look very nice and can be used over again... The size/shape of stone varies, depending on your personal choice

[noshed]

Lotty shop or 99p shop.
Pencil is the way to go - get a 2b