Plan it like a wedding (weeks, even months in advance). Don't announce until you have everything ready to go and all is perfected. Choose your date wisely.
If top flight marketers in your niche are doing a similar launch, around that time, defer and help promote their launch. You simply need to postpone.
That hot product launch formula niche will buy from you but not 7 days after Jeff Walker relaunches his product launch formula. Help his JV, then 6 or 7 weeks later it's all forgotten and you can do well with your launch.