Heres some info on 10 meter activity. 

The band is open if you basically hear anything other than static.   

1. Listen for signals on the FT8 frequency at 28.074 mHz.  If you hear anything, the band is open.

2. Look for activity on the map or list at https://www.dxmaps.com/spots/mapg.php?Lan=E  Click on the 28 mHz tab.  See the band activity.  For visually impaired, click the list tab on the upper left.  Calls, time, mode etc is displayed. 

3. Listen for CW beacons up the band between 28.1 and 28.3 mHz.  These are usually all low power slow speed CW with a repeating pattern of callsign, grid, power, location.  The letter V or dits are sometimes sent in Morse a few times at the start, followed by DE (this is).  /B designates it’s a beacon.

4. Beacons are usually less than 10 watts so these are QRP.  Beacons can fade in and out depending on the location and conditions. 

5. The beacon call usually will be identified on QRZ so if you manage to decode it, look these up and you can get the details.  These are some examples I pulled down last Sunday. 

28.196 VE7MTY/B CN89  https://www.qrz.com/db/VE7MTY

28.222 N1NSP/B FM17RL https://www.qrz.com/db/N1NSP

28.260 KC4QLP/B   several stations on this  https://www.qrz.com/db/KC4QLP/B

28.270 WA3NFV/B (PA)  https://www.qrz.com/db/WA3NFV

28.3 K6FRC/B https://www.qrz.com/db/K6FRC

6. Good practice for even brute force decoding (writing the dits and dahs and looking up the letters).  Otherwise you can use a CW decoder on FLdigi to figure out the signal.   

7. For SSB tune up above 28.300 in to the voice band.  Anything you hear means the band is open. 

8. Finally, there are beacon lists that can help with this.  Radio Reference has some.  Several others out there. 

The same process can be done for 6 meters.

Mark