There have been excellent IPO's too! We need due diligence to be done throughly and not be moved by analysts and brokerage house recomendations.
Any company, before entering IPO market, does lot of window dressing on their accounting books and at least for a short while, their overall practices looks better than what is written in commerce textbooks. Kinda like, how folks decorate house during Diwali. Doing "due diligence" and reading all that fine print will usually reveal nothing alarming or bad.
NOW FOR SOME PRACTICAL/USABLE/EFFICIENT APPROACH based on FACTS
FACT: As a matter of practice, companies do provide shares to individuals on private basis prior to IPO.
In 1990s-2000s, the IPO was always at the face value of the share and 90% of shares had face value of 10 regardless of its book value and minimum purchase quantity was 100. Company whose book value was below face value had practically no subscription chances and the fundamental rule that "market price will approach book value"
Hence, in most IPOs, prices used to rise immediately after listing. This made trading in IPO very very attractive. I too had doubled my own meagre capital of 1000 rs 3 times in row. Strategy: Buy in IPO. Sell off on 2nd or 3rd day of listing
Nowadays, with offer price much above face value, probability of those pre-IPO share owners wanting to book profit is very high and hence chances of price dropping is very high. Many of them want to cash in on listing.
If you want to play IPO now, assuming you have ample time to do your "due diligence", either approach the IPO-ing company and try to (legally) avail the pre-IPO shares privately or find opportunity to Short at listing.