AdvancedUpdated Dec 16, 2025
Fine-tuning FLUX with LoRA
Deep dive into preparing datasets, hyperparameter tuning, and deploying your own custom LoRA models for unique styles.
DMW
Dr. Marcus Webb
ML Research Lead
20 min read
What is LoRA?
LoRA (Low-Rank Adaptation) is a technique for efficiently fine-tuning large models by training only a small number of additional parameters. Benefits:
- Smaller file sizes - LoRAs are typically 10-200MB
- Faster training - Hours instead of days
- Composable - Combine multiple LoRAs
- No base model changes - Use with any compatible model
Preparing Your Dataset
Dataset Requirements
- Minimum images: 10-20 (more is better)
- Recommended: 50-200 images
- Resolution: At least 512x512, ideally 1024x1024
- Consistency: Similar style/subject across images
Image Selection Tips
- High quality, well-lit images
- Consistent subject/style
- Various angles and poses
- Clean backgrounds when possible
- No watermarks or text
Captioning Your Images
Each image needs a caption describing it:
text
photo_001.jpg -> "A portrait of sks person, professional lighting, studio background" photo_002.jpg -> "A sks person smiling, outdoor natural lighting, park background"
Use a trigger word (like sks) to identify your trained subject.
Training Configuration
python
from abstrakt import AbstraktClient
client = AbstraktClient()
# Upload training images
training_job = client.training.create({
"model": "flux-lora",
"config": {
"trigger_word": "sks",
"steps": 1000,
"learning_rate": 1e-4,
"batch_size": 1,
"resolution": 1024,
"network_rank": 32,
"network_alpha": 16
},
"images": [
{"url": "https://...", "caption": "A sks person..."},
{"url": "https://...", "caption": "A sks person..."},
# ... more images
]
})Hyperparameter Guide
Learning Rate
- 1e-4: Standard, good default
- 5e-5: More conservative, better for faces
- 2e-4: Faster training, risk of overfitting
Steps
- 500-800: Quick training, basic style
- 1000-1500: Balanced, recommended
- 2000+: Deep training, risk of overfitting
Network Rank
- 8-16: Smaller LoRA, subtle effects
- 32: Balanced, recommended
- 64-128: Larger LoRA, stronger effects
Monitoring Training
python
# Check training status
status = client.training.get(training_job.id)
print(f"Status: {status.state}")
print(f"Progress: {status.progress}%")
print(f"Current step: {status.current_step}")
# Training logs
for log in status.logs:
print(f"[{log.step}] Loss: {log.loss}")Using Your LoRA
Once training completes:
python
result = client.run("fal-ai/flux/dev", {
"input": {
"prompt": "A portrait of sks person as a medieval knight",
"loras": [
{
"path": "your-lora-id",
"scale": 0.8 # LoRA strength
}
]
}
})Combining Multiple LoRAs
python
result = client.run("fal-ai/flux/dev", {
"input": {
"prompt": "A sks person in a beautiful landscape",
"loras": [
{"path": "person-lora-id", "scale": 0.9},
{"path": "landscape-style-lora", "scale": 0.5}
]
}
})Troubleshooting
| Issue | Solution |
|---|---|
| Overfitting | Reduce steps, lower learning rate |
| Underfitting | More steps, higher learning rate |
| Style bleeding | Adjust LoRA scale (0.5-0.8) |
| Poor quality | More/better training images |
Best Practices
- Start simple - 500 steps, default settings
- Iterate - Train multiple versions with different settings
- Test thoroughly - Try various prompts
- Version control - Save different LoRA versions
- Document - Keep notes on training configs
Next Steps
- Master prompting for your LoRA
- Learn batch processing
- Explore RAG integration
#fine-tuning#lora#flux#training