What tips did he give you? We have a woodburner but there are no chimney sweeps here. I have rods and brushes but have never done it before.
It is going to differ depending on chimney type and woodburner type. the big one in the living room has the flue horizontally out of the back and then t'd upwards into the original coal chimney and has a flue port on the vertical. For that one the top cooker plates get lifted out and brush/vacuum out the area above the backboiler, reach through the horizonatl section and hand pick out all the debris that fell into the low part of the T and/or remove the bottom cap (but it's awkward to get at) then vacuum that out.
He showed me quite how large a brush you can get in through the flue port althugh he wasn't a fan of brushes with plastic centres (wear too quick). You can also use a mirror to look up the chimney. Obviously you keep turning the brushes/rod clockwise to keep the joints tightening.
He also demonstrated how to tap and feel the cowl so you measure the chimney length before you go with a close fitting brush and apparently if you do get unlucky and lose a wide brush up there (and can't hook it out) then light a few sheets of newspaper in the stove and the bristles should melt so it falls down.
For my hobby-shed woodburner which is way more modern the only access to the flue is from inside.. a straight shot out the top. But for that you have to remove all the liner fire bricks, inner top plate and grate (which allows good cleaning) and then brush in through the door and up... even my cheap rods bend that 90 degs.
Things I dont have to worry about is old fashioned chimneys with ledges and steps inside them and mine are fitted with antibird cowls so I;m not pulling rook nests out.
top down cleaning wouldn't work here.. quite apart from the nuisance of undoing the cowl straps and replacing .. the main house chimney is scary access that I woudnt dream of trying and the hobbyshed flue is just steel above the shed roof (pitched with lightweight aluminium faux tile sheets) so you'ld need ladder access and boards to spread your weight and then very long arms to reach the rest of the distance (or unclip the whole top section)