Can I claim money spent on clothes for work on my tax return?

I am self-employed, and am just filling out my first Tax Return. I am not sure what I can put down as expenses, and would really appreciate some advice on this.
I work mainly from home, can I use any of my rent, electricity, heating bills?
I have a bill pay phone which I use mainly for work, but also personal calls. Can I charge any of this, or would I have to do it call by call (I pay a monthly fee, and never usually go over this, except for business calls from abroad).
Can I use expenses on clothes I buy for work, or make-up, which I only wear at work (I have to give business workshops with corporate clients).

Is there anything else I am not thinking of that I could add in as a business expense?

Where self-employed and looking to claim business expenses, the best way to look at it is to thing 'If I was employed and conducting the same function, would I be able to claim the expenses from my employer'?

On this basis, clothing and make-up would not be allowed. However the costs of conducting business from home would allow you to claim an appropriate portion of your utility bills, including phone cost on an appropriate % basis.

From the info given, travel expenses for the workshops would be allowable (petrol/train tickets, overnight stays and client entertainment).

Also, have a look at the Revenue guide to Starting in Business : http://www.revenue.ie/leaflets/it48.pdf

As a self-employed person, you should really get an accountant to look at your full personal situation to get the best advice. Especially when starting out in business, you should start on a sound footing. And until then, keep receipts for everything!