Short answer — the ones frequent flyers most commonly recommend are:

• Airline/loyalty-program websites (e.g., United, ANA, Air France/KLM, Singapore, etc.)

  • Pros: most reliable availability, no middleman fees, easiest changes/cancellations if booked on the carrier’s own award inventory.
  • Cons: some sites are clunky and don’t show partner availability or multi-carrier routings.

• Alliance / partner websites (search each alliance member when needed)

  • Pros: can uncover partner seats not shown on your home program; necessary for complex itineraries.
  • Cons: requires knowing which partners to check and how to price partners’ awards.

• Meta award search engines / tools

  • AwardHacker — quick free idea of which programs could get you a given long-haul route with points.
  • Point.Me (paid) — modern paid search/booking service that scrapes many programs, shows routing options and sometimes books for a fee.
  • Pros: saves time by aggregating possibilities and showing which programs/pricing to try.
  • Cons: may miss live-updates, some features behind paywalls, fees for booking help.

• Expert/paid broker services (award brokers and concierge services)

  • Examples used by many frequent flyers: Juicy Miles / award booking services or independent award brokers.
  • Pros: good for complex itineraries, family travel, or when you don’t want to deal with phone calls and routing rules.
  • Cons: service fees (often hundreds); you give the broker access to your points or you transfer miles to them in some models — check security & terms.

• Tools for monitoring and seat alerts

  • ExpertFlyer (paid) and some airline-specific alert tools — lets you set alerts for award space and immediate notification when a seat opens.
  • Pros: excellent for snagging last-minute or newly-released inventory.
  • Cons: subscription cost and some airlines block full data.

Practical tips frequent flyers follow

• Start at the airline whose miles you already have, then check likely partners (use alliance maps).
• Use meta-search tools (AwardHacker/Point.Me) to shortlist candidate programs and routing ideas.
• Set ExpertFlyer or airline alerts for your exact dates/route — award space appears unpredictably.
• Be flexible on date/time/airport and look for one-stop routings; sometimes routing through a partner hub reveals business class space.
• Compare total out‑of‑pocket costs (taxes & fuel surcharges) and the broker/service fees before booking.
• When in doubt, book directly with the carrier that issues the award (if possible) for easier changes; if you use a broker, confirm how refunds/cancellations are handled.

If you want, tell me the route(s) and which points/miles you have and I’ll recommend the best programs and search strategy for finding long‑haul business class availability.