Like a number of the other respondents to this thread, I no longer have any uncomfortable feelings buying feminine items even though, at present, I still present as male. This includes both female items for myself and feminine hygiene items etc. for my wife or daughter. That said, I'm still not at the stage where I would feel comfortable going into a boutique type shop where I'd feel more conspicuous but the larger high street chains present no problems nowadays.
As it happens, I was browsing the women's sections in a clothes shop and shoe shop yesterday. I did get a strange look from a very young (probably mid-teens) assistant while admiring a dress but I guess, at that age, she'd not yet got the maturity or knowledge to understand. After her double-take, she just moved on and left me be. In the shoe shop, where I'd previously just had sneaky looks at the women's section on the way to the mens, I stopped for a proper look and, after maybe half a minute, surprised myself that I'd become a little too interested for someone in guy clothes!
The other thing I've found is that, since coming out to my SO (without going into too much detail, I had to as I thought she'd found something of mine (she hadn't) and, as a result she gave me the ultimatum to quit or she'd throw me out), I've now got no excuse if she asks me to go and buy something for her or my daughter so I just get on with it.
Amanda