So, I'm a mum of 3 (two in RG uni & one in sec sch). Yes I know RG is a marketing tool. One's reading Law and the other Mechatronics and Robotics.
Things I did/do:
Encouraged reading – we took part in the library’s reading challenge every single year.
One did not like reading so I would play them CDs of books. You can get these from libraries. Back in the day you could also get them from daily papers. I was not a Telegraph reader but bought it and others when they were doing literary giveaways like that.
Kept up my church attendance (born, baptised and married RC) so they could get into the very good church primary and secondary local to us. Fee paying was not an option I qualified for, even with concessions and I did not wish to put them under the stress of a grinding academic workload to possibly qualify - or not - for a bursary or scholarship.
Put them in holiday playschemes that took them on a wide range of trips to places of interest in and out of London (I cannot drive due to disability).
Never used Sky, only Freeview so all of us limited our television viewing.
Took/take them on Eurostar, Megabus, Ferries, the tube etc. They’ve also flown. This in my opinion exposed them to different ways of doing things, emphasised adaptability and helped their practical learning.
Taught them to cook, they now cook for the family. Suring lockdown challenged them to come out of it with a new accomplishment. They /we all did!
Pushed them to use their judgement. When they were young and I took them on walks, I would make them find the way home with no or minimal input from me
Built their confidence by promoting (imposing) church activity (altar serving, taking readings or the offertory) so they had contact with a diverse range of people and stood up and “performed solo in public” in a safe familiar setting.
Spoke about my country of origin very positively, exposing them to Nigerian writers such as Atinuke, Achebe, Ifeoma Onyefulu. We also explained about names, meanings and why they had them rather than “English names”.
It was important that they did not see Africa as an amorphous continent, so we demonstrated pride in our personal roots, and wide general knowledge of our similarities and differences. It does help being South East Londoners.
Always was happy for them to take part in school sport but pushed them towards other in-school activities eg debating, current affairs and so on because you want them to know that black people can do more than just entertainment or sports.
Made them speak to adults. From primary school age, took them to my/their dad’s work, as a way of reinforcing the manners and behaviours we taught them at home.
Promoted a second language - not always successfully. But at least they know where’s more out there than English 
I plugged heavily into my network. Not having been educated here, I am able to show them, very easily, scores of role models in all kinds of professions. For instance, someone I went to school with was portrayed by Will Smith in a film so you can imagine how intrigued they were that their mother knew him.
I’ve deliberately listed free or affordable things that I did to raise aspirations. Like other posters, we discussed money, debt and so on with them. Both uni students are working to fund most of their living costs and we pay for their accommodation so they only take out the tuition loan. We also emphasise acquiring and developing transferable skills and the need to aim high.
NOTE: They were not always eager participants in all activities. Carrots and sticks helped (especially that one time I took them to touch typing class).
One thing I have tried to do is equip them for the unknown. There are no guarantees in life, so I've tried not to map out a life/career plan for and with them. No matter the skills they have, if I do not help strengthen their resilience, adaptability, sense of perspective, they will not be able to use them to advantage. We have also emphasised that they can make choices, and that choices have consequences, good and bad, expected and unexpected.
@samosamo I did not have any plan when I was doing any of this, I was merely replicating what I had experienced and what I had seen others do that I thought might benefit my children. If I have any regrets it's that I never was able to find a nearby Scouts Troop and I was too scared to send them to ATE which one of my friends did with hers. They loved it and made friends from many countries and backgrounds and mine often asked to go but I said no. She heartily recommends it.