[strangerachael]

I'm still with the pencil and paper. I have a book I started just after I got the alloment. I draw a rough plan in pencil at the start of the year, then as I plant everything write over with pen so I have a record of what was actually put in and where from year to year.   

Me too. I use it for everything from seed shopping lists, potato varieties, planting/sowing dates and notes for next year. I do a pencil sketch plan every winter, which gets tweaked several times until everything is in and then I use it to plan next year's plot. Very useful and straightforward. I don't always remember to record sowing dates, but I can usually find them on my blog somewhere.

[tosca100]

Plan? There's a gap!!!!!!!! Fill it.

[Christine]

Draw a picture called a plan in Excel - change it when excess of one thing causes a stretch of an area. Keep a final amended item at end of season to give me a clue about what not to plant in the same area again.

Plans can be fouled up by too much of one thing growing and too little of another.   

[Junie]

 This is only my second year, but I have made labels for each crop using a DYMO machine ( The old fashioned sort). and each group of veg for crop rotation is a different colour, I will then designate the beds a colour each year, and treat accordingly - I only came up with this idea this year - so do not know if it will works - but it suits my simple brain!

[boosh]

Plan? There's a gap!!!!!!!! Fill it.

Now that sounds like a good plan 

[Paul Plots]

To be honest my plot planning happens as I stand there and look at it...

The "Plan" is just a record of where things went and when. Useful for the following year to avoid same crops in same places - helps with my "almost" rotation system.

I need another half-plot to make rotation easier - and then the free time to manage it   

[woodburner]

Designing the layout of your plot to see how much space you will have left for veg beds once you've planted the fruit bushes and perennials, and placed the coldframe and compost bins etc, is useful to a degree, but something always seems to happen so that I have never actually managed to stick to the plan, so I have given up on that sort of planning, however, there is a lot to be said for drawing a plan of your allotment/garden/plot to record what is where, and what was there before.

As for planning rotations . . . 
Seriously though, as long as you know what was there before, and when you last added manure or lime, you can plant appropriately.