No offense, but if you're still asking this question, then stick with 1 lot. It sounds you have much to learns in regards to money management. Once you master money management you'll learn advanced techniques, like trading with multiple lots, scaling in, scaling out, pyramiding, etc.
I'd recommend you read Trading for Living" and "Come Into My Trading Room" both written by Alexandar Elder. Once you finish, read them one more time. Do this and you'll be closer to profitability my friend.
I agree with oooogglemoogle, we, beginners must strart trading with only one lot, read and experience first, learn everything One way to learn is to post in this kind of forum, and when we finally believe that we have learned the tricks, then you start trading with more lots...
From an experienced trader's view,
Depends on the current risk exposure.
Max risk at any time: 2%
Reasonable SL: 100 pips for a H4 trader; 60 pips for a H1 trader and so on....
For a 60K account, 2%= 1200
For Standard lots pip value= 10; so we make sure that regardless of the number of trades, the maximum lot
size for all trades should have a max exposure of 1200.
So an example of this:
Trade 1: 0.5 lot; SL= 100pips; exposure= 500
Trade 2: 0.7 lot; SL= 100 pips; exposure= 700
Once the SL is moved to BE for any of the trades, then a new equivalent lot size can be opened.
If the winning trades has 100 pips already locked in, then a newer lot of equivalent size can be opened.
The rest is quite complicated.
Bottom line: We have maintained the 2%, calculated lot sizes according to the exposure and the rest is up to the trading team.