Hardy Tropicals UK

I know the world of compost and potting mixes is an endless one, and there are lots of great threads already ( many of which I have read through). This year I do want to put a bit more care in to my potting mixes, as it clearly makes a difference, but don't have an endless budget in order to source all the different components.

Obviously the exact requirements varies from plant to plant, but just wondered what a good general purpose potting mix would be (ratio wise) using (or not omitting) the following:

Good quality peat-free general purpose compost
John Innes No. 2
Perlite
Sand/grit
Garden soil
Compost waste

Anything else that would really make a difference to add in .... thats fairly easily/cheaply sourced?

I can then tweak from the basic recipe according to plant's needs.

You could do with adding bark.

I don't tend to use garden soil in a potting mix, it tends to compact and goes 'sour'. I also don't weigh the ratios. I mix roughly a bucket of home made compost with a bucket of mpc, use a peat free type if you're minted or value the environment...I'm not and I do, but I'm not minted!
I mix this with half bucket of coarse sand bought from builders merchants, it's washed, good enough for me. I do add well composted leaf mulch when I've got it, it gives a nice silky feel to the mix but adds only bulk no real nutrient value. Perlite gets added at a rough 50/50 mix but tend to use this for potting on cuttings and divisions.

Everybody develops their own favourite, there's no right or wrong. Do a seasonal trial with a few differing combinations you'll soon find one that works well for your own uses.

I have a different variation for pots in full sun compared to ones in shade. To do with moisture retention and drainage.