Did it for several years with IG Index, finspreads, capital spreads and Cantor. Capital used to have the best spreads and IG the best service.
Emotionally it's very hard, if you get in on some extremely liquid stocks, the spread is high (especially with a guaranteed stop-loss), but so is the movement. I remember one day having swings on £5 (Buy to open) on Rio Tinto at about +/-£200.
The toughest thing, apparenetly, is learning to cut yor losses, for me it was staying in them and not closing the position before nice profits. Also, with some of the more inviting stocks, Inchcape to name one i remember, i got stopped out several times because i wasn't prepared to take the swings needed, so merely gambled, on a lower-low and hoped it'd be good. It eventually climbed like a rocket (i wasn't aboard), but i soon learned there are certain volatile stocks you steer clear of. IG for instance used to let you trade at £2 min on some of the bigger boys, but if you wanted in on a lesser stock, you had minimum of £5, sometimes £10.
Derwent Valley Holdings was one i remember, i needed to pay at £5 a point and with spread i was about -£200 before it had even moved. That is why it's tough on the emotions, £1 per point at say Capital Spreads is great, and to be fair their spreads are amazing, but you stick that £1 a point on a currency pair with someone and fuck me, you'll wish you weren't born!

Some of the easiest trades, both emotionally and financially, i found, were using Fibonacci retracements on inter hourly binaries within the Dow 30 and Ftse 100. Oh and stay away from US stocks and currencies, you will honestly lose everything in minutes if your stop-loss is tight.
It's also a bit of a myth about losing more than you have, they'll let you deposit what you want, and you can lose everything in the account in seconds if your stupid. There are plenty of safeguards in place, to prevent you owing them, because that's something that used to happen quite a bit. Now, i think this is across the board, you can only trade with a guaranteed stop, positioned at a maximum amount of points, +/-, the number of multiples of your position size remaining in the account.
If you only deposit £1k or something many trades will be off the radar from the word go, either that or one position will take up your entire balance, until your stop loss is moved up or down accordingly. Try binaries, do it with £1, there's only a 1 or 2 point spread and they either close at 100 or 0, but that's a whole other animal.
Also, for any intra day stuff, get live software, Reuters Trader used to be one of the best, but it's pretty pricey. Sharescope Pro was pretty good and well priced, but don't buy any delayed software, it's near pointless imo. I think e-signal works out pretty good as well, from recollection, but we're talking 3-4 years ago or seomthing.

Good luck and hold tight.