AstraVanMan wrote:

1. M25, then A40/M40 to Hanger Lane [1], then A406 to Brent Cross, taking
A41 towards London. Third left (excluding the ones on the sliproad just as
you join the A41) into Wayside, 2nd left into Armitage Road, straight across
two sets of lights, and follow the road up to Meadway until Kingsley Way
(about 0.8 miles), then left onto Kingsley Way, straight over the first set
of lights (A1 junction),

Interesting way to avoid Henlys Corner.

and right at the top onto East End Road, which
leads into East Finchley. Then just follow the A504 through East Finchley,
Muswell Hill

technically "following" the A504 through Muswell Hill means by-passing
Queens Avenue.

Hornsey,

I use A1 Lyttleton Road/Aylmer Road then left onto A1000 for a few
yards then through Woodside Avenue, Cranley Gardens, The Chine and left
into Park Road before joining the A504 by turning right into Priory
Road.

leading up to Seven Sisters,

Which means at Turnpike Lane you must turn right then left again,
because the obvious "ahead" is the A1080 Westbury Road which takes you
up to Lordship Lane.

And as you're going to head for Seven Sisters anyway you may as well
use Philip Lane which is the B153.

and up to Walthamstow
from there. From joining East End Road things might be a little slow, but
far less worse than the alternatives IMHO.

I wouldn't be so sure.

2. M25 around to the A10 junction, then A10 towards London, and first left
towards Enfield Lock - then follow the A1055 past Enfield Lock and
Brimsdown, either picking up the North Circular where you come to it, or
just carry on to Tottenham Hale and go into Walthamstow from there.
Either of those should avoid most of the worst traffic blackspots for that
journey.

No, you should leave at J24 and go through the A111.

[1] You could go A30/A312, or M4/A312, but you're probably as well just
staying on the M25 if you're starting on it, and if you go A30/A312 the
queues can be a pain coming up to the M4.

There are rat-runs for that too, but the main road is generally faster.
You'd be surprised how often staying on the main road and moving slowly
with the traffic queue is actually faster than the seemingly flowing
alternative routes.