On one hand you don't want to be perceived as a constant source of criticism. That would make the team members feel unsafe talking to you. Especially that would apply to the ones who are still learning and therefore not very confident in their job. And those are the team members who need feedback most.
On the other hand it is important for the team members to get feedback, both positive and negative, on all the aspects of their work. However it is not feasible for you to be so closely engaged with everybody on the team at all the times to be able to provide such an amount of constructive and detailed feedback.
There are two ways how you can deliver feedback to the team members: directly and indirectly.
Direct feedback is shared verbally or in writing, during a 1-on-1 meeting or in a group. As a general rule of thumb it works better to share negative direct feedback with a person during 1-on-1 meetings and positive also in a group setting. Sharing your feedback directly has usually the strongest emotional impact. At the same time it poses the risk of misunderstanding and misinterpretation. You should use this powerful tool wisely, as your words will be often taken personally and remembered for a long time. Make sure you are not falling into the
Winner's Syndrome pattern while giving direct feedback to the team members. When giving direct feedback to the whole team, avoid the
Labeling anti-pattern.
Indirect feedback is working for you all the time, also when you are away from the team, working with the stakeholders or spending time on holidays. As a team leader you should invest time and effort into creating and maintaining a system of feedback loops, that will allow the team members to assess themselves the quality of their work and the status of the projects they are working on.