A good way to streamline approvals for small value items is to introduce a Self Approval step into your approval process. The Self Approval delegation limit is set on the user and applies to all spend within that delegation.
If configured, the process will check to see if the user purchasing has self approval delegation before looking for a delegated approver. For example if a Self Approval limit is set on the user for $300, then all spend below $300 will be automatically approved and not require delegated approval. Note that it cannot be tailored to specific scenarios unless the Group Self Approval option is used which is outlined in this article: Group Self Approval Process
If you do not want to have any self approval option available, then you can either not set a Self Approval limit of your users, or you can choose to remove the Self Approval rule from your approval process entirely.