The key is to search first, but yes, it is allowed to post a request for tips.

The key is to post a meaningful title (which you did in this thread) such as "advice needed for cheapest routing NYC to LON in July." Thread titles like "Help needed" or " Can you help me" usually are paid no attention.

And sometimes the best forum is for the destination in the regional forum list. If I wanted help being cheap in Charlotte I'd post in The South.