My herb runs usually include 5 herb patches, 4 flower patches, and my cactus patch.  I will occasionally do watermelons, but generally not.  I hope you enjoy!  PM me if you have any questions :P.

First, I go to the bank and grab my supplies.  You need all 4 tools, some seeds, and some teleports.  If you do not have the required magic level or quest requirements to do the "Fertile Soil" spell, then add some super compost (you don't need to fill the invy with it, there's a few places you can bank along the way).  If I were to plant watermelons as well, I would simply add 24 watermelon seeds to my inventory.

Here are the spells I use during my farm run.  If you have the higher level requirement, you can use the group teleport spells and get more xp for the same cost.

First, I teleport to trollheim (you have to run at parts, so I do this first to assure high run energy)

I then run west and take the path to get to the trollheim patch (My Arm's big adventure required)

Always remember to put on magic secateurs before picking herbs!  You MUST wear them.

When picked, I use fertile soil on the patch (increases the # of herbs you can pick as well as helps to protect the herbs from disease [I still use here even though the herbs are immune to disease at this patch])

I clean my herbs and use them on the tool leprechaun in order for him to note them!

Time for the next location!  I teleport via ectophial and then run west to the canifis patch.  I always give it a second to allow the ectophial to refill.

Here's our first limpwurt plant!  I pick the herbs and the limps (always gives 3).  I use fertile soil on my limpwurts as well.

You can note limps as well as herbs!

My next location is the falador patch.  It's much faster to teleport using the Explorer's ring or even a glory teleport to draynor than it is to teleport to falador.

After that patch (or anytime, really), I teleport to the duel arena and head south to my cactus patch.

I pick my cactus spines for 3 spines.  DO NOT REPLANT THE CACTUS.  You only need to plant it once and it will continuously grow spines.

You can even note cactus spines!

Next, I teleport to the fishing guild and head east to the Ardougne patch.  This method is faster than teleporting to Ardougne and running or using the legend's guild fairy ring.

Here I pick my limpwurts and my herbs, then clean my herbs and note everything.

Sometimes you get lucky and get a lot of herbs!

My last location is Catherby.  I like to come here last because there is a bank right next to the patch so I can easily stock up for my next adventure.  If you were using super composts in lieu of fertile soil, this is a good location for the middle of the trip so you can restock on super compost.

Sometimes herbs die :(

Not bad for 5 minutes of work!  I didn't factor in runes cost, but the total runes used were: 9 law runes, 36 astrals, 18 natures. (about 10k gp)

Not bad for about 5 minutes of work!  Herbs take about 80 minutes to grow, so in a few hours, you can make a lot of money!  Thanks for reading this.  I hope you enjoyed.