An easy way to improve your writing and editing is to remove unnecessary words. A tautology is the use of redundant words. So, tautologies are one form of redundancy that you can remove from your writing (and speaking) – once you are aware of them.
A tautology is the repetition of meaning in two consecutive words, or the needless repetition of an idea. Examples of tautologies include: 
    - Free gift
 
    - Added bonus
 
    - Adequate enough
 
    - New innovation
 
    - Forward planning
 
    - Short summary
 
    - Unexpected surprise
 
    - Past history
 
    - Reiterate again
 
    - Joint cooperation.
 
In each of the examples above one of the words can be removed. 
For instance, instead of saying, a ‘new innovation’, say an ‘innovation’ – because to innovate it must be new. The word new is redundant and adds no value.
What about a ‘short summary’? Well, if it’s not short it’s not a summary. So, use ‘summary’ only. The word short is redundant.
Or an ‘unexpected surprise’? If the surprise is expected it isn’t a surprise, is it? So, use ‘surprise’. The word unexpected is redundant.
Removing tautologies applies to all types of writing – from tenders to features and everything in between. It will make your writing clearer and prevent it from being redundant and superfluous.