small selling and bigger other capital gain

1. I know (think) that if one sells one's own clothes and gain it is less than 1k one does not need to inform HMRC 2. I know that if one has capital gains eg from property, one need to inform HMRC and to pay taxes if such occured Question : what aobut altogheter ? CG from property, less than 1 K from selling own clothes ? Simple answer shoud be: add toghether, calculate CG. BUT, and it is the most important, as it looks "against" the reason of tax. If one has CG from property eg 8K, and CG from selling own clothes for eg 500, total is 8500, but buying own clothes was eg 2500, it can take CG down to 6k, and nothing tax. Can one deduct price of buying own clothes ? if yes, is bank account enough ? . Or just do not add and do not deduct this small selling ?

Hi answerpls,
Capital Gains Tax is a tax on the profit when you sell (or ‘dispose of’) something (an ‘asset’) that’s increased in value.  
The trading income allowance of £1000 applies if you are self employed and disposing of stock to make a profit, it is not part of capital gains.  
With capital gains, you have an annual exempt allowance in the current tax year of £3000.  
Have a look at Capital Gains Tax for more information.
Thank you.