You mentioned that you're always drawn to the stuff you liked pre-baby - well that's good I think, you possibly just need to adapt to your life now though.
So I would think about what 'outfits' you need, ie, stuff for playgroup, stuff for seeing friends, something for going out in. Then go and try a lot of stuff on, paying particular attention to what colours look good on you.
I'd personally order a lot of things online, perhaps 4 colours of the same style top and see which colour really looks good on you. But then I didn't enjoy shopping in shops with a small baby and rather tried stuff on at home.
Are you pear or apple shaped? Its just I am an apple and find dresses very hard indeed, I really need shift style and unfortunately they tend to be more formal so don't work for my life as a SAHM.
I do tend to stick to the classic SAHM uniform of jeans, nice tops with scarves etc.
Also worth looking at blogs to see how people put things together, I love tiffany at the moment.
I'm not sure about the Debenhams personal shopping purely because its not a shop I ever look in - would it be possible to switch to John Lewis at all as their stock range is better in my opinion. I think they also do a colours thing there now too.