If this aspect sits in your natal chart, the odds are you don't think of yourself as carrying anything special. Sun trine Venus works so quietly that the people who own it are usually the last to notice it. Others tell you that you're easy to be around, that you have a knack for putting people at ease, that you've got taste and a sense of proportion — and you shrug and assume everyone's like that. Not everyone is.
Venus in harmony with the Sun means your ability to be liked grew out of the core of who you are, rather than being added on top later as a defence mechanism. You didn't study charm from books, you didn't drill a smile in the mirror, you never picked up the techniques of winning people over. It's simply there, the way the colour of your eyes is there, or the timbre of your voice. You can sit silent in the corner of a room and somebody will still drift over to say hello. You can pay no attention to your clothes and somehow still look put-together. It isn't magic; it's an aspect.
I see people like this in consultations often, and there's a characteristic thread running through them: they underrate the resource. Because the trine works in the background, it doesn't register as a talent. A talent, the reasoning goes, is something that comes hard and through some pain — and when a thing comes easily, surely that just makes it ordinary. That logic strands a great many trine-people in the position of "this is fine as it is". They could have been actors, negotiators, sellers of beautiful and expensive things, the owners of galleries and salons, people who advise others on style. Instead they often settle into work that pays a little above average and lets them keep their head down.
The second recurring storyline is easy relationships. Not in the sense of "I don't need anyone", but in the sense that there is nearly always someone around. Sun trine Venus tends to skip the long stretches of solitude. A relationship ends today, and a month later there's a new person who, honestly, is also rather nice. That's convenient, and there's a price for the convenience: depth can be slow to arrive, because there is never any scarcity to force it. When there are always enough people willing to love you, the motivation to work on yourself and on the partnership quietly drops.
Venus adds another thing here that I rate highly: the ability to receive. Not in the sense of putting up with someone's faults, but literally taking what is offered — money, compliments, help, love. A lot of people struggle to accept a gift; some part of them refuses it, devalues it, feels it as a debt to be repaid. Someone with Venus trine the Sun simply doesn't carry that block. It's offered, they take it, they say thank you, they move on. That is a rare and genuinely valuable knack, and especially so where money is concerned.
But even here there's a reverse side. The ease of receiving can slide into the ease of carelessness. If money arrives without effort, it tends to be spent without much arithmetic. If people love you without putting you through your paces, you can come to treat them as a given. The trine doesn't teach you to value things, because it never lets you taste their absence — and at some point life tends to arrange a situation in which you have to work out, for yourself, what actually matters to you.
Sun trine Venus does not do the work for you. It supplies a backdrop on which it's easier to be yourself and easier to be liked. What you build on that backdrop is entirely down to you. To see how your own particular set of aspects plays out alongside this trine, it's worth reading the chart as a whole rather than this one contact in isolation — and reading it as something to reflect on, not a script for your life.