[ClaireMc]

I have nasty looking critters eating every strawberry as it becomes ripe (and they don't even eat the whole strawberry - they just nibble and move on).  They look very much like woodlice.

And the brassicas are all covered in grey aphids and their yellow eggs.

Will I have to resort to pesticides or are there friendlier solutions available for either?

[WG.]

yellow eggs are from Cabbage White Butterfly - rub them off ASAP.  These disposable latex gloves are great if you don't like the thought of it.

Sounds like you might also have mealy aphid.  How is your ladybird population?

[ClaireMc]

Plenty of ladybirds in evidence.  Would you recommend the washing-up liquid method to see off the aphids? Or is that an urban myth?

Ooh look it's raining. Hurrah.

[WG.]

You have hinted at non-organic solutions (please update your Profile) so perhaps someone will offer advice.

Organic : Soapy water with or without garlic puree might deter them.  Derris should kill them (along with plenty else).