The front wheel is correct but I would move the D lock at the back. It is only round a wheel and a mudguard.

Your current method means the frame could be stolen by undoing the wheel bolts and lifting away. Can't see exactly how the mudguards are fixed and they might complicate it a bit but not much.

I'd suggest low on the seat tube just above the chain ring and then loop the cable round the front and back wheels and into the D lock.

Edit: forgot. Don't bother looping up through the seat like that. If they want to steal that with the cable there it's only two bolts. It's only one without the cable but if you were still worried you can get security seatpost bolts

Lot of good advice here, but I'll add that no lock is perfect. If someone wants your bike, they will take it. This is good enough to keep someone from walking away with your bike, but anyone with tools can break any bike lock on the market.

Just keep that in mind when you're spending time and energy, and especially money, protecting your bike. It's a very nice bike, but it is replaceable if the worst should happen.

As others have said, U-lock through frame and rear wheel if possible. Otherwise not bad. I've also taken to using a motion detector alarm on my last bike packing trip.
https://www.amazon.com/dp/B07MFBV7TW?psc=1&ref=ppx_yo2ov_dt_b_product_details

I don't know what bike theft is like in your area, but here in nl all bikes have a rear lock that's mounted to the bike to keep the rear wheel secure. In the big cities people also usually attach their bikes to solid objects using a chain through the frame and the front wheel. I would be more concerned about your lock- such string locks are very easy to cut through with a bolt cutter. My recommendation would be to get a strong chain link lock with a plastic sleeve. I'm sure you can find such locks online where you live.

times have changed but sheldon's pages are still a relatively good source for bicycles

that thin cable is better than nothing and i too use it sometimes but you shouldn't trust it.

security of your bike depends on where you lock it more than how you lock it. Most of the time a uLock around the rear wheel through the frame is enough (even in paris!)

That's a classy bike. Where I live you can't even leave your bike fully locked up though. I can bring my bike inside at my current job but I would drive otherwise.

Cordless angle grinder and a CD case of cutting wheels and the vast majority of locks can be cut like butter. Aluminum needs a different cutting disc and can explode the ones for steel. When considering the lock that has multiple metals to contaminate cutting wheels for an outdoor project, we tried cutting stacks of aluminum and stainless. It's an improvement but if someone has discs to swap for and familiarity with the tools and metals I'd say it could still be done under 15 minutes. If they are just druggies the mixed metal one could gum up the discs and take maybe up to 45 min if they don't realize they have the wrong tool config.

Hopefully your area doesn't have overly capable assholes though. Or maybe cops that are better than what we have.

If the lock is long enough to put the wheel through it, it is usually also possible to include one of the seat stays as well.

Cutting both the wheel and a seat stay is possible, of course, but it severely devaluates the bicycle and also makes it unrideable so the thief can't use it to escape.

Locking the bike through the seat tube is not as good because the bike is still rideable after cutting through it.

Some additonal images:

Looks good 👍

This whole post is making me think of the hidden 6th song on The decemberists album 5 songs EP.

It starts off with, "I'm really sorry steven, your bicycles been stolen..."

As has been mentioned, use your U lock to lock the frame. If you can include the wheel and the frame that's best but often needs a big U lock.

I recommend purchasing wheel security devices such as pinheads or pitlocks and then you don't really need to worry about locking your wheels so much

Lock that U lock around the frame of your bike, otherwise pretty good: They do sell bigger U locks, so it would be worth investing in one.