This is how I warm up my Reddit accounts, and about 70% of them work normally.
- Use the Adspower browser with a proxy.
- Use a clean email to create a new account.
- For the first two days, absolutely do not post any comments. Just browse Reddit for about 10 minutes each day, and join 1-2 large subreddits (like r/AskReddit). On the third day, you can upvote a few posts.
- In the following days, you can start commenting, but only make 1-2 comments per day on large and new-user-friendly subreddits (like r/AskReddit).
Continue this for about 10 days, and your account should be working normally. Focus on developing your comment karma more than your post karma, as Reddit values comment karma more.
I hope this helps!