Since I wrestle with this about once per month, here is the IAM policy to allow full user access to an S3 bucket.

{
   "Statement":[
      {
         "Effect":"Allow",
         "Action":[
            "s3:ListAllMyBuckets"
         ],
         "Resource":"arn:aws:s3:::*"
      },
      {
         "Effect":"Allow",
         "Action":[
            "s3:ListBucket",
            "s3:GetBucketLocation"
         ],
         "Resource":"arn:aws:s3:::bucket-name"
      },
      {
         "Effect":"Allow",
         "Action":[
            "s3:PutObject",
            "s3:GetObject",
            "s3:DeleteObject"
         ],
         "Resource":"arn:aws:s3:::bucket-name/*"
      }
   ]
}