Vouchers should only be used for goods that are scarce or cause heavy pollution
This is the goal, by in the meantime, labor vouchers would have to be used until we reach a level of entirely socialized production.
So any good that can be hoarded or where it doesn't make sense to give "free" access - food, clothes, "luxury" gadgets and "luxury" goods (i.e.: anything that goes past the immediate standard of said society) - would be bought using labor vouchers.
For example, it makes sense to give school supplies to children free of charge because they all roughly need the same items.
But (leisure) clothing is much more individual - we have different sizes, different styles, different tastes, minors grow, people can gain or lose weight etc. - for that reason, clothing would need to be subject to a labor voucher market, rather than be distributed free of charge like school supplies.
The same goes for food: Sure we can imagine a basket of staple foods that everyone needs, but diets are different, tastes are different, there exist allergies, people come from different parts of the world and have different cuisines and so on, so it makes sense to give the consumer the choice of what he wants to buy using labor vouchers rather than giving out a standard food supply kit free of charge.
Why not have a customizable kit? Well, it would be logistically difficult to have too much of individualization whenever free kits and supplies are involved (until we reach communism). So anything that cannot be standardized would need to be bought by labor vouchers.
But for example, digital goods would always be free. Most ("essential") services would be free - healthcare, insurance, education, housing, mass transit, utilties, waste management, communal eating at work- and schoolplaces, telecommunications, sports, fitness, wellness, hygiene/beauty, entertainment, cultural endeavours, media products and so on. They would be financed from the public at large (meaning taxes + using the surplus value of the labor). The result would be that the incomes of the people would be lower, but they would only need said income for less things than in capitalist societies so it wouldn't matter. They would, in the short-term, only need to buy food, buy clothes, buy furniture that goes beyond what the public housing offers, buy gadgets and goods that go beyond what the state offers free of charge, finance vacations to foreign countries and visit restaurants/cafes and so on - whereas in capitalism, we would need to pay rent, insurance, transit fees, telecommunication, television, utilities and so on.
The goal would be to make more and more goods free of charge and use more and more of the surplus value to make this happen, until one day, there would be almost no personal income left - simply because all the labor produced by said society would go into subsidizing these free goods, so that you don't need any currency to buy these goods and services because they would be free anyway. This is when communism would be reached.