Before initiating the data transfer, thoroughly understand the structure of your Recreation database. Identify tables, fields, and data types that need to be transferred. Document the relationships between tables if any, as this will help in mapping the data to MongoDB's document-oriented structure.

Use SQL queries to extract data from the Recreation database. Depending on the database type (e.g., MySQL, PostgreSQL), connect to the database using a command-line tool or a database management application, and execute SQL queries to retrieve data. Export the data into a CSV or JSON format for easier manipulation. For example, `SELECT FROM table_name INTO OUTFILE 'data.csv'` can be used in MySQL.

If MongoDB isn't already installed, download and install it from the [official MongoDB website](https://www.mongodb.com/try/download/community). Follow the installation instructions for your operating system. Once installed, start the MongoDB server using the `mongod` command and ensure it's running correctly by connecting to it with the `mongo` shell.

Design a schema for how the data should be structured in MongoDB. Unlike SQL databases, MongoDB is schema-less, but it's crucial to have a clear schema design to ensure data integrity and efficient querying. Decide on the collections, and how documents should be structured, including field names and nested documents if necessary.

Using a scripting language like Python, JavaScript, or a simple command-line tool, transform the extracted data to match your MongoDB schema. For instance, in Python, you can use the `pandas` library to read CSV data, manipulate it, and then convert it to a JSON format that suits your MongoDB design. This step ensures that data types and structures are compatible with MongoDB.

Use the MongoDB shell or a scripting language to insert the transformed data into MongoDB. With Python, you can use the `pymongo` library to connect to your MongoDB instance and insert data. For example:
```python
from pymongo import MongoClient
client = MongoClient('localhost', 27017)
db = client['your_database']
collection = db['your_collection']
with open('transformed_data.json') as f:
data = json.load(f)
collection.insert_many(data)
```
This step involves iterating over your data and inserting it into the appropriate MongoDB collections.

After inserting the data, perform checks to ensure that the data has been transferred accurately and completely. Use the MongoDB shell or a GUI tool like MongoDB Compass to query the data and verify that all entries are present and correctly structured. Additionally, run consistency checks to ensure that relationships and data integrity have been maintained as per the original Recreation database.

By following these steps, you can effectively migrate data from a Recreation database to MongoDB without using third-party connectors or integrations.