Tip 45 : Don't undersell yourself
This should go without saying, but many people suffer from sharp pangs of modesty when writing their personal statement. This is potentially a very harmful trait, because you can bet that you'll be competing against candidates who are unafraid to take advantage of every accomplishment, learning experience and positive evaluation they've ever had. In these cases it's not hard to guess who's going to get the interview.
Try looking at it this way. Imagine that you're a strong candidate for a position - perhaps 20% stronger than a rival applicant. Now, for the sake of modesty, you wind up underselling yourself by holding back achievements, or not providing specific details that would make your application more impressive. If your rival now writes a powerful personal statement, they could end up appearing to be your equal, or worse they could even be selected in your stead.
Clearly that's not what you want.
The most common form of underselling is not providing specific figures where they are available. For instance, many people feel that including precise financial or statistical figures to demonstrate their suitability for a post will be construed as arrogance. This is highly unlikely, as employers/admissions officers are really only interested in selecting the best applicants.
So go ahead and make the most of you knowledge, skills, achievements and experience - You've literally earned it.
Tip 46 : Don't oversell yourself
Okay, so you should sell yourself to the hilt, no questions about that. But there are limitations.
For starters, you should not lie on your personal statement - these things have tendency of being found out and coming back to bite you - but beyond that, you should avoid making too big a deal of something. For the most part, this is simply the avoidance of hyperbole.
For instance, if as an office manager you implemented a new stationery buying system, you should certainly mention that if you are targeting a novice management job. If it's true, you could even say that you revolutionised the stationery buying system - that's a genuine achievement, and whilst the word revolutionised is a bit strong, there's nothing wrong with including it if it's what you actually did. What you shouldn't do is exaggerate the impact that had on the office as a whole. Stationery buying tends to be something of a bugbear in most offices, so insinuating that your improvements made life easier for X number of colleagues is fine; suggesting that it permanently resolved all tensions within the office, however, is unbelievable.
Before you laugh that example off as ludicrous, by the way, it's a real one that I read in an application a few years ago.
Again, exact facts and figures are your friend here, as that kind of empirical evidence can't be argued with in the same way that intangible benefits - say, office harmony - can.