Short answer

• Use a modern award-search engine to scan many programs at once (Seats.aero is the current favorite), then verify and book on the airline/loyalty program that gives you the best price/terms. (seats.aero.)

Why (and the practical workflow)

1. Decide how flexible you are (exact dates, +/- days, airports, cabin). Flexibility hugely increases your chances of finding saver award seats. (cntraveler.com)
2. Run a multi-program search with a dedicated award-search engine (fast way to see options across alliances and partners). Seats.aero, Point.me and similar services aggregate award space and let you set alerts; Seats.aero is fast, supports alliance-wide searches and has live searches/alerts for Pro users. (seats.aero.)
3. Use ExpertFlyer (or a comparable GDS-based tool) to confirm seat/booking class and to set seat/award alerts for specific flights — especially helpful for premium cabins and specific fare buckets. (expertflyer.com)
4. Cross-check the winning routing on the actual loyalty program you plan to use (Air Canada Aeroplan, United, Alaska, Virgin Atlantic, etc.). Some programs show more partner space or have better pricing for a route — so check the program you’ll actually redeem through before moving points. Never transfer transferable points until you confirm the award is ticketable. (thepointsguy.com)
5. If you can’t find what you want online, call the frequent‑flyer program (agents can sometimes see/book partner space) or use a specialist award-booking service/concierge. (thepointsguy.com)

Tools and what they’re best for

• Seats.aero — best all-around aggregator for speed, alliance-wide searches, region/city-code searches, and alerts (free tier + inexpensive Pro). Good first stop. (seats.aero.)
• ExpertFlyer — great for pulling specific fare/award booking classes, upgrade inventory and detailed alerts; widely used by power users. (Paid.) (expertflyer.com)
• Point.me (and similar paid services) — user-friendly, shows which transferable programs will work and often flags booking instructions; mixed user reviews so always verify on the carrier website. (nerdwallet.com)
• Airline/program websites — authoritative for ticketing. Use United/Aeroplan/LifeMiles/Alaska/etc. depending on alliance/route. Some carriers (or their partners) won’t release all premium space to all programs, so you must check the specific program you plan to use. (thepointsguy.com)

Important caveats

• Award space changes fast and tools can disagree; always confirm availability (and the price in miles + fees) on the program you’ll actually use before transferring points. (wsj.com)
• Some airlines are stingy with partner access for premium cabins (e.g., Singapore, some Delta partner pricing rules); which program can book a given seat varies by carrier and route. (thepointsguy.com)
• Paid tools have limits, quirks and occasional inaccuracies — treat them as guides, not guarantees. (nerdwallet.com)

Quick recommended setup (if you book award travel even occasionally)

• Sign up for Seats.aero (free to try; Pro if you want alerts/live search up to a year). (seats.aero.)
• Create ExpertFlyer (or equivalent) alerts for any hard-to-find premium cabins. (expertflyer.com)
• Keep a short list of the best programs for your usual routes (e.g., Aeroplan/United/Avianca LifeMiles for Star Alliance; Alaska/AAdvantage/British Airways for oneworld partners) and always verify on that program before transferring transferable points. (thepointsguy.com)

If you want, tell me the route(s) and dates (or date range) you care about and I’ll suggest which programs/tools to check first and a prioritized search plan.